1 /* 2 * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "jvm.h" 27 #include "asm/macroAssembler.hpp" 28 #include "classfile/classLoader.hpp" 29 #include "classfile/systemDictionary.hpp" 30 #include "classfile/vmSymbols.hpp" 31 #include "code/codeCache.hpp" 32 #include "code/icBuffer.hpp" 33 #include "code/vtableStubs.hpp" 34 #include "interpreter/interpreter.hpp" 35 #include "logging/log.hpp" 36 #include "memory/allocation.inline.hpp" 37 #include "os_share_bsd.hpp" 38 #include "prims/jniFastGetField.hpp" 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.inline.hpp" 44 #include "runtime/java.hpp" 45 #include "runtime/javaCalls.hpp" 46 #include "runtime/mutexLocker.hpp" 47 #include "runtime/osThread.hpp" 48 #include "runtime/sharedRuntime.hpp" 49 #include "runtime/stubRoutines.hpp" 50 #include "runtime/thread.inline.hpp" 51 #include "runtime/timer.hpp" 52 #include "utilities/align.hpp" 53 #include "utilities/events.hpp" 54 #include "utilities/vmError.hpp" 55 56 // put OS-includes here 57 # include <sys/types.h> 58 # include <sys/mman.h> 59 # include <pthread.h> 60 # include <signal.h> 61 # include <errno.h> 62 # include <dlfcn.h> 63 # include <stdlib.h> 64 # include <stdio.h> 65 # include <unistd.h> 66 # include <sys/resource.h> 67 # include <pthread.h> 68 # include <sys/stat.h> 69 # include <sys/time.h> 70 # include <sys/utsname.h> 71 # include <sys/socket.h> 72 # include <sys/wait.h> 73 # include <pwd.h> 74 # include <poll.h> 75 #ifndef __OpenBSD__ 76 # include <ucontext.h> 77 #endif 78 79 #if !defined(__APPLE__) && !defined(__NetBSD__) 80 # include <pthread_np.h> 81 #endif 82 83 // needed by current_stack_region() workaround for Mavericks 84 #if defined(__APPLE__) 85 # include <errno.h> 86 # include <sys/types.h> 87 # include <sys/sysctl.h> 88 # define DEFAULT_MAIN_THREAD_STACK_PAGES 2048 89 # define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13 90 #endif 91 92 #ifdef AMD64 93 #define SPELL_REG_SP "rsp" 94 #define SPELL_REG_FP "rbp" 95 #else 96 #define SPELL_REG_SP "esp" 97 #define SPELL_REG_FP "ebp" 98 #endif // AMD64 99 100 #ifdef __FreeBSD__ 101 # define context_trapno uc_mcontext.mc_trapno 102 # ifdef AMD64 103 # define context_pc uc_mcontext.mc_rip 104 # define context_sp uc_mcontext.mc_rsp 105 # define context_fp uc_mcontext.mc_rbp 106 # define context_rip uc_mcontext.mc_rip 107 # define context_rsp uc_mcontext.mc_rsp 108 # define context_rbp uc_mcontext.mc_rbp 109 # define context_rax uc_mcontext.mc_rax 110 # define context_rbx uc_mcontext.mc_rbx 111 # define context_rcx uc_mcontext.mc_rcx 112 # define context_rdx uc_mcontext.mc_rdx 113 # define context_rsi uc_mcontext.mc_rsi 114 # define context_rdi uc_mcontext.mc_rdi 115 # define context_r8 uc_mcontext.mc_r8 116 # define context_r9 uc_mcontext.mc_r9 117 # define context_r10 uc_mcontext.mc_r10 118 # define context_r11 uc_mcontext.mc_r11 119 # define context_r12 uc_mcontext.mc_r12 120 # define context_r13 uc_mcontext.mc_r13 121 # define context_r14 uc_mcontext.mc_r14 122 # define context_r15 uc_mcontext.mc_r15 123 # define context_flags uc_mcontext.mc_flags 124 # define context_err uc_mcontext.mc_err 125 # else 126 # define context_pc uc_mcontext.mc_eip 127 # define context_sp uc_mcontext.mc_esp 128 # define context_fp uc_mcontext.mc_ebp 129 # define context_eip uc_mcontext.mc_eip 130 # define context_esp uc_mcontext.mc_esp 131 # define context_eax uc_mcontext.mc_eax 132 # define context_ebx uc_mcontext.mc_ebx 133 # define context_ecx uc_mcontext.mc_ecx 134 # define context_edx uc_mcontext.mc_edx 135 # define context_ebp uc_mcontext.mc_ebp 136 # define context_esi uc_mcontext.mc_esi 137 # define context_edi uc_mcontext.mc_edi 138 # define context_eflags uc_mcontext.mc_eflags 139 # define context_trapno uc_mcontext.mc_trapno 140 # endif 141 #endif 142 143 #ifdef __APPLE__ 144 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) 145 // 10.5 UNIX03 member name prefixes 146 #define DU3_PREFIX(s, m) __ ## s.__ ## m 147 # else 148 #define DU3_PREFIX(s, m) s ## . ## m 149 # endif 150 151 # ifdef AMD64 152 # define context_pc context_rip 153 # define context_sp context_rsp 154 # define context_fp context_rbp 155 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip) 156 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) 157 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax) 158 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) 159 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) 160 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) 161 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) 162 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) 163 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) 164 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) 165 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) 166 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) 167 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) 168 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) 169 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) 170 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) 171 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) 172 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) 173 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 174 # define context_err uc_mcontext->DU3_PREFIX(es,err) 175 # else 176 # define context_pc context_eip 177 # define context_sp context_esp 178 # define context_fp context_ebp 179 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip) 180 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp) 181 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax) 182 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) 183 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) 184 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx) 185 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) 186 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi) 187 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi) 188 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) 189 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 190 # endif 191 #endif 192 193 #ifdef __OpenBSD__ 194 # define context_trapno sc_trapno 195 # ifdef AMD64 196 # define context_pc sc_rip 197 # define context_sp sc_rsp 198 # define context_fp sc_rbp 199 # define context_rip sc_rip 200 # define context_rsp sc_rsp 201 # define context_rbp sc_rbp 202 # define context_rax sc_rax 203 # define context_rbx sc_rbx 204 # define context_rcx sc_rcx 205 # define context_rdx sc_rdx 206 # define context_rsi sc_rsi 207 # define context_rdi sc_rdi 208 # define context_r8 sc_r8 209 # define context_r9 sc_r9 210 # define context_r10 sc_r10 211 # define context_r11 sc_r11 212 # define context_r12 sc_r12 213 # define context_r13 sc_r13 214 # define context_r14 sc_r14 215 # define context_r15 sc_r15 216 # define context_flags sc_rflags 217 # define context_err sc_err 218 # else 219 # define context_pc sc_eip 220 # define context_sp sc_esp 221 # define context_fp sc_ebp 222 # define context_eip sc_eip 223 # define context_esp sc_esp 224 # define context_eax sc_eax 225 # define context_ebx sc_ebx 226 # define context_ecx sc_ecx 227 # define context_edx sc_edx 228 # define context_ebp sc_ebp 229 # define context_esi sc_esi 230 # define context_edi sc_edi 231 # define context_eflags sc_eflags 232 # define context_trapno sc_trapno 233 # endif 234 #endif 235 236 #ifdef __NetBSD__ 237 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 238 # ifdef AMD64 239 # define __register_t __greg_t 240 # define context_pc uc_mcontext.__gregs[_REG_RIP] 241 # define context_sp uc_mcontext.__gregs[_REG_URSP] 242 # define context_fp uc_mcontext.__gregs[_REG_RBP] 243 # define context_rip uc_mcontext.__gregs[_REG_RIP] 244 # define context_rsp uc_mcontext.__gregs[_REG_URSP] 245 # define context_rax uc_mcontext.__gregs[_REG_RAX] 246 # define context_rbx uc_mcontext.__gregs[_REG_RBX] 247 # define context_rcx uc_mcontext.__gregs[_REG_RCX] 248 # define context_rdx uc_mcontext.__gregs[_REG_RDX] 249 # define context_rbp uc_mcontext.__gregs[_REG_RBP] 250 # define context_rsi uc_mcontext.__gregs[_REG_RSI] 251 # define context_rdi uc_mcontext.__gregs[_REG_RDI] 252 # define context_r8 uc_mcontext.__gregs[_REG_R8] 253 # define context_r9 uc_mcontext.__gregs[_REG_R9] 254 # define context_r10 uc_mcontext.__gregs[_REG_R10] 255 # define context_r11 uc_mcontext.__gregs[_REG_R11] 256 # define context_r12 uc_mcontext.__gregs[_REG_R12] 257 # define context_r13 uc_mcontext.__gregs[_REG_R13] 258 # define context_r14 uc_mcontext.__gregs[_REG_R14] 259 # define context_r15 uc_mcontext.__gregs[_REG_R15] 260 # define context_flags uc_mcontext.__gregs[_REG_RFL] 261 # define context_err uc_mcontext.__gregs[_REG_ERR] 262 # else 263 # define context_pc uc_mcontext.__gregs[_REG_EIP] 264 # define context_sp uc_mcontext.__gregs[_REG_UESP] 265 # define context_fp uc_mcontext.__gregs[_REG_EBP] 266 # define context_eip uc_mcontext.__gregs[_REG_EIP] 267 # define context_esp uc_mcontext.__gregs[_REG_UESP] 268 # define context_eax uc_mcontext.__gregs[_REG_EAX] 269 # define context_ebx uc_mcontext.__gregs[_REG_EBX] 270 # define context_ecx uc_mcontext.__gregs[_REG_ECX] 271 # define context_edx uc_mcontext.__gregs[_REG_EDX] 272 # define context_ebp uc_mcontext.__gregs[_REG_EBP] 273 # define context_esi uc_mcontext.__gregs[_REG_ESI] 274 # define context_edi uc_mcontext.__gregs[_REG_EDI] 275 # define context_eflags uc_mcontext.__gregs[_REG_EFL] 276 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 277 # endif 278 #endif 279 280 address os::current_stack_pointer() { 281 #if defined(__clang__) || defined(__llvm__) 282 void *esp; 283 __asm__("mov %%" SPELL_REG_SP ", %0":"=r"(esp)); 284 return (address) esp; 285 #elif defined(SPARC_WORKS) 286 void *esp; 287 __asm__("mov %%" SPELL_REG_SP ", %0":"=r"(esp)); 288 return (address) ((char*)esp + sizeof(long)*2); 289 #else 290 register void *esp __asm__ (SPELL_REG_SP); 291 return (address) esp; 292 #endif 293 } 294 295 char* os::non_memory_address_word() { 296 // Must never look like an address returned by reserve_memory, 297 // even in its subfields (as defined by the CPU immediate fields, 298 // if the CPU splits constants across multiple instructions). 299 300 return (char*) -1; 301 } 302 303 address os::Bsd::ucontext_get_pc(const ucontext_t * uc) { 304 return (address)uc->context_pc; 305 } 306 307 void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) { 308 uc->context_pc = (intptr_t)pc ; 309 } 310 311 intptr_t* os::Bsd::ucontext_get_sp(const ucontext_t * uc) { 312 return (intptr_t*)uc->context_sp; 313 } 314 315 intptr_t* os::Bsd::ucontext_get_fp(const ucontext_t * uc) { 316 return (intptr_t*)uc->context_fp; 317 } 318 319 // For Forte Analyzer AsyncGetCallTrace profiling support - thread 320 // is currently interrupted by SIGPROF. 321 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 322 // frames. Currently we don't do that on Bsd, so it's the same as 323 // os::fetch_frame_from_context(). 324 // This method is also used for stack overflow signal handling. 325 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 326 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 327 328 assert(thread != NULL, "just checking"); 329 assert(ret_sp != NULL, "just checking"); 330 assert(ret_fp != NULL, "just checking"); 331 332 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); 333 } 334 335 ExtendedPC os::fetch_frame_from_context(const void* ucVoid, 336 intptr_t** ret_sp, intptr_t** ret_fp) { 337 338 ExtendedPC epc; 339 const ucontext_t* uc = (const ucontext_t*)ucVoid; 340 341 if (uc != NULL) { 342 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc)); 343 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc); 344 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc); 345 } else { 346 // construct empty ExtendedPC for return value checking 347 epc = ExtendedPC(NULL); 348 if (ret_sp) *ret_sp = (intptr_t *)NULL; 349 if (ret_fp) *ret_fp = (intptr_t *)NULL; 350 } 351 352 return epc; 353 } 354 355 frame os::fetch_frame_from_context(const void* ucVoid) { 356 intptr_t* sp; 357 intptr_t* fp; 358 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 359 return frame(sp, fp, epc.pc()); 360 } 361 362 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) { 363 intptr_t* sp; 364 intptr_t* fp; 365 ExtendedPC epc = os::Bsd::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp); 366 return frame(sp, fp, epc.pc()); 367 } 368 369 bool os::Bsd::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) { 370 address pc = (address) os::Bsd::ucontext_get_pc(uc); 371 if (Interpreter::contains(pc)) { 372 // interpreter performs stack banging after the fixed frame header has 373 // been generated while the compilers perform it before. To maintain 374 // semantic consistency between interpreted and compiled frames, the 375 // method returns the Java sender of the current frame. 376 *fr = os::fetch_frame_from_ucontext(thread, uc); 377 if (!fr->is_first_java_frame()) { 378 // get_frame_at_stack_banging_point() is only called when we 379 // have well defined stacks so java_sender() calls do not need 380 // to assert safe_for_sender() first. 381 *fr = fr->java_sender(); 382 } 383 } else { 384 // more complex code with compiled code 385 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above"); 386 CodeBlob* cb = CodeCache::find_blob(pc); 387 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) { 388 // Not sure where the pc points to, fallback to default 389 // stack overflow handling 390 return false; 391 } else { 392 *fr = os::fetch_frame_from_ucontext(thread, uc); 393 // in compiled code, the stack banging is performed just after the return pc 394 // has been pushed on the stack 395 *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp())); 396 if (!fr->is_java_frame()) { 397 // See java_sender() comment above. 398 *fr = fr->java_sender(); 399 } 400 } 401 } 402 assert(fr->is_java_frame(), "Safety check"); 403 return true; 404 } 405 406 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 407 // turned off by -fomit-frame-pointer, 408 frame os::get_sender_for_C_frame(frame* fr) { 409 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 410 } 411 412 intptr_t* _get_previous_fp() { 413 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__) 414 intptr_t **ebp; 415 __asm__("mov %%" SPELL_REG_FP ", %0":"=r"(ebp)); 416 #else 417 register intptr_t **ebp __asm__ (SPELL_REG_FP); 418 #endif 419 // ebp is for this frame (_get_previous_fp). We want the ebp for the 420 // caller of os::current_frame*(), so go up two frames. However, for 421 // optimized builds, _get_previous_fp() will be inlined, so only go 422 // up 1 frame in that case. 423 #ifdef _NMT_NOINLINE_ 424 return **(intptr_t***)ebp; 425 #else 426 return *ebp; 427 #endif 428 } 429 430 431 frame os::current_frame() { 432 intptr_t* fp = _get_previous_fp(); 433 frame myframe((intptr_t*)os::current_stack_pointer(), 434 (intptr_t*)fp, 435 CAST_FROM_FN_PTR(address, os::current_frame)); 436 if (os::is_first_C_frame(&myframe)) { 437 // stack is not walkable 438 return frame(); 439 } else { 440 return os::get_sender_for_C_frame(&myframe); 441 } 442 } 443 444 // Utility functions 445 446 // From IA32 System Programming Guide 447 enum { 448 trap_page_fault = 0xE 449 }; 450 451 extern "C" JNIEXPORT int 452 JVM_handle_bsd_signal(int sig, 453 siginfo_t* info, 454 void* ucVoid, 455 int abort_if_unrecognized) { 456 ucontext_t* uc = (ucontext_t*) ucVoid; 457 458 Thread* t = Thread::current_or_null_safe(); 459 460 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away 461 // (no destructors can be run) 462 os::ThreadCrashProtection::check_crash_protection(sig, t); 463 464 SignalHandlerMark shm(t); 465 466 // Note: it's not uncommon that JNI code uses signal/sigset to install 467 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 468 // or have a SIGILL handler when detecting CPU type). When that happens, 469 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To 470 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 471 // that do not require siginfo/ucontext first. 472 473 if (sig == SIGPIPE || sig == SIGXFSZ) { 474 // allow chained handler to go first 475 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 476 return true; 477 } else { 478 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219 479 return true; 480 } 481 } 482 483 JavaThread* thread = NULL; 484 VMThread* vmthread = NULL; 485 if (os::Bsd::signal_handlers_are_installed) { 486 if (t != NULL ){ 487 if(t->is_Java_thread()) { 488 thread = (JavaThread*)t; 489 } 490 else if(t->is_VM_thread()){ 491 vmthread = (VMThread *)t; 492 } 493 } 494 } 495 /* 496 NOTE: does not seem to work on bsd. 497 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 498 // can't decode this kind of signal 499 info = NULL; 500 } else { 501 assert(sig == info->si_signo, "bad siginfo"); 502 } 503 */ 504 // decide if this trap can be handled by a stub 505 address stub = NULL; 506 507 address pc = NULL; 508 509 //%note os_trap_1 510 if (info != NULL && uc != NULL && thread != NULL) { 511 pc = (address) os::Bsd::ucontext_get_pc(uc); 512 513 if (StubRoutines::is_safefetch_fault(pc)) { 514 os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 515 return 1; 516 } 517 518 // Handle ALL stack overflow variations here 519 if (sig == SIGSEGV || sig == SIGBUS) { 520 address addr = (address) info->si_addr; 521 522 // check if fault address is within thread stack 523 if (thread->on_local_stack(addr)) { 524 // stack overflow 525 if (thread->in_stack_yellow_reserved_zone(addr)) { 526 if (thread->thread_state() == _thread_in_Java) { 527 if (thread->in_stack_reserved_zone(addr)) { 528 frame fr; 529 if (os::Bsd::get_frame_at_stack_banging_point(thread, uc, &fr)) { 530 assert(fr.is_java_frame(), "Must be a Java frame"); 531 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr); 532 if (activation.sp() != NULL) { 533 thread->disable_stack_reserved_zone(); 534 if (activation.is_interpreted_frame()) { 535 thread->set_reserved_stack_activation((address)( 536 activation.fp() + frame::interpreter_frame_initial_sp_offset)); 537 } else { 538 thread->set_reserved_stack_activation((address)activation.unextended_sp()); 539 } 540 return 1; 541 } 542 } 543 } 544 // Throw a stack overflow exception. Guard pages will be reenabled 545 // while unwinding the stack. 546 thread->disable_stack_yellow_reserved_zone(); 547 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 548 } else { 549 // Thread was in the vm or native code. Return and try to finish. 550 thread->disable_stack_yellow_reserved_zone(); 551 return 1; 552 } 553 } else if (thread->in_stack_red_zone(addr)) { 554 // Fatal red zone violation. Disable the guard pages and fall through 555 // to handle_unexpected_exception way down below. 556 thread->disable_stack_red_zone(); 557 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 558 } 559 } 560 } 561 562 if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) { 563 // Verify that OS save/restore AVX registers. 564 stub = VM_Version::cpuinfo_cont_addr(); 565 } 566 567 // We test if stub is already set (by the stack overflow code 568 // above) so it is not overwritten by the code that follows. This 569 // check is not required on other platforms, because on other 570 // platforms we check for SIGSEGV only or SIGBUS only, where here 571 // we have to check for both SIGSEGV and SIGBUS. 572 if (thread->thread_state() == _thread_in_Java && stub == NULL) { 573 // Java thread running in Java code => find exception handler if any 574 // a fault inside compiled code, the interpreter, or a stub 575 576 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { 577 stub = SharedRuntime::get_poll_stub(pc); 578 #if defined(__APPLE__) 579 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. 580 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops). 581 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from 582 // being called, so only do so if the implicit NULL check is not necessary. 583 } else if (sig == SIGBUS && !MacroAssembler::uses_implicit_null_check(info->si_addr)) { 584 #else 585 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 586 #endif 587 // BugId 4454115: A read from a MappedByteBuffer can fault 588 // here if the underlying file has been truncated. 589 // Do not crash the VM in such a case. 590 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 591 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; 592 if (nm != NULL && nm->has_unsafe_access()) { 593 address next_pc = Assembler::locate_next_instruction(pc); 594 stub = SharedRuntime::handle_unsafe_access(thread, next_pc); 595 } 596 } 597 else 598 599 #ifdef AMD64 600 if (sig == SIGFPE && 601 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 602 stub = 603 SharedRuntime:: 604 continuation_for_implicit_exception(thread, 605 pc, 606 SharedRuntime:: 607 IMPLICIT_DIVIDE_BY_ZERO); 608 #ifdef __APPLE__ 609 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { 610 int op = pc[0]; 611 612 // Skip REX 613 if ((pc[0] & 0xf0) == 0x40) { 614 op = pc[1]; 615 } else { 616 op = pc[0]; 617 } 618 619 // Check for IDIV 620 if (op == 0xF7) { 621 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO); 622 } else { 623 // TODO: handle more cases if we are using other x86 instructions 624 // that can generate SIGFPE signal. 625 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 626 fatal("please update this code."); 627 } 628 #endif /* __APPLE__ */ 629 630 #else 631 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 632 // HACK: si_code does not work on bsd 2.2.12-20!!! 633 int op = pc[0]; 634 if (op == 0xDB) { 635 // FIST 636 // TODO: The encoding of D2I in i486.ad can cause an exception 637 // prior to the fist instruction if there was an invalid operation 638 // pending. We want to dismiss that exception. From the win_32 639 // side it also seems that if it really was the fist causing 640 // the exception that we do the d2i by hand with different 641 // rounding. Seems kind of weird. 642 // NOTE: that we take the exception at the NEXT floating point instruction. 643 assert(pc[0] == 0xDB, "not a FIST opcode"); 644 assert(pc[1] == 0x14, "not a FIST opcode"); 645 assert(pc[2] == 0x24, "not a FIST opcode"); 646 return true; 647 } else if (op == 0xF7) { 648 // IDIV 649 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 650 } else { 651 // TODO: handle more cases if we are using other x86 instructions 652 // that can generate SIGFPE signal on bsd. 653 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 654 fatal("please update this code."); 655 } 656 #endif // AMD64 657 } else if ((sig == SIGSEGV || sig == SIGBUS) && 658 MacroAssembler::uses_implicit_null_check(info->si_addr)) { 659 // Determination of interpreter/vtable stub/compiled code null exception 660 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 661 } 662 } else if (thread->thread_state() == _thread_in_vm && 663 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 664 thread->doing_unsafe_access()) { 665 address next_pc = Assembler::locate_next_instruction(pc); 666 stub = SharedRuntime::handle_unsafe_access(thread, next_pc); 667 } 668 669 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 670 // and the heap gets shrunk before the field access. 671 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 672 address addr = JNI_FastGetField::find_slowcase_pc(pc); 673 if (addr != (address)-1) { 674 stub = addr; 675 } 676 } 677 678 // Check to see if we caught the safepoint code in the 679 // process of write protecting the memory serialization page. 680 // It write enables the page immediately after protecting it 681 // so we can just return to retry the write. 682 if ((sig == SIGSEGV || sig == SIGBUS) && 683 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 684 // Block current thread until the memory serialize page permission restored. 685 os::block_on_serialize_page_trap(); 686 return true; 687 } 688 } 689 690 #ifndef AMD64 691 // Execution protection violation 692 // 693 // This should be kept as the last step in the triage. We don't 694 // have a dedicated trap number for a no-execute fault, so be 695 // conservative and allow other handlers the first shot. 696 // 697 // Note: We don't test that info->si_code == SEGV_ACCERR here. 698 // this si_code is so generic that it is almost meaningless; and 699 // the si_code for this condition may change in the future. 700 // Furthermore, a false-positive should be harmless. 701 if (UnguardOnExecutionViolation > 0 && 702 (sig == SIGSEGV || sig == SIGBUS) && 703 uc->context_trapno == trap_page_fault) { 704 int page_size = os::vm_page_size(); 705 address addr = (address) info->si_addr; 706 address pc = os::Bsd::ucontext_get_pc(uc); 707 // Make sure the pc and the faulting address are sane. 708 // 709 // If an instruction spans a page boundary, and the page containing 710 // the beginning of the instruction is executable but the following 711 // page is not, the pc and the faulting address might be slightly 712 // different - we still want to unguard the 2nd page in this case. 713 // 714 // 15 bytes seems to be a (very) safe value for max instruction size. 715 bool pc_is_near_addr = 716 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 717 bool instr_spans_page_boundary = 718 (align_down((intptr_t) pc ^ (intptr_t) addr, 719 (intptr_t) page_size) > 0); 720 721 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 722 static volatile address last_addr = 723 (address) os::non_memory_address_word(); 724 725 // In conservative mode, don't unguard unless the address is in the VM 726 if (addr != last_addr && 727 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 728 729 // Set memory to RWX and retry 730 address page_start = align_down(addr, page_size); 731 bool res = os::protect_memory((char*) page_start, page_size, 732 os::MEM_PROT_RWX); 733 734 log_debug(os)("Execution protection violation " 735 "at " INTPTR_FORMAT 736 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr), 737 p2i(page_start), (res ? "success" : "failed"), errno); 738 stub = pc; 739 740 // Set last_addr so if we fault again at the same address, we don't end 741 // up in an endless loop. 742 // 743 // There are two potential complications here. Two threads trapping at 744 // the same address at the same time could cause one of the threads to 745 // think it already unguarded, and abort the VM. Likely very rare. 746 // 747 // The other race involves two threads alternately trapping at 748 // different addresses and failing to unguard the page, resulting in 749 // an endless loop. This condition is probably even more unlikely than 750 // the first. 751 // 752 // Although both cases could be avoided by using locks or thread local 753 // last_addr, these solutions are unnecessary complication: this 754 // handler is a best-effort safety net, not a complete solution. It is 755 // disabled by default and should only be used as a workaround in case 756 // we missed any no-execute-unsafe VM code. 757 758 last_addr = addr; 759 } 760 } 761 } 762 #endif // !AMD64 763 764 if (stub != NULL) { 765 // save all thread context in case we need to restore it 766 if (thread != NULL) thread->set_saved_exception_pc(pc); 767 768 os::Bsd::ucontext_set_pc(uc, stub); 769 return true; 770 } 771 772 // signal-chaining 773 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 774 return true; 775 } 776 777 if (!abort_if_unrecognized) { 778 // caller wants another chance, so give it to him 779 return false; 780 } 781 782 if (pc == NULL && uc != NULL) { 783 pc = os::Bsd::ucontext_get_pc(uc); 784 } 785 786 // unmask current signal 787 sigset_t newset; 788 sigemptyset(&newset); 789 sigaddset(&newset, sig); 790 sigprocmask(SIG_UNBLOCK, &newset, NULL); 791 792 VMError::report_and_die(t, sig, pc, info, ucVoid); 793 794 ShouldNotReachHere(); 795 return false; 796 } 797 798 // From solaris_i486.s ported to bsd_i486.s 799 extern "C" void fixcw(); 800 801 void os::Bsd::init_thread_fpu_state(void) { 802 #ifndef AMD64 803 // Set fpu to 53 bit precision. This happens too early to use a stub. 804 fixcw(); 805 #endif // !AMD64 806 } 807 808 809 // Check that the bsd kernel version is 2.4 or higher since earlier 810 // versions do not support SSE without patches. 811 bool os::supports_sse() { 812 return true; 813 } 814 815 bool os::is_allocatable(size_t bytes) { 816 #ifdef AMD64 817 // unused on amd64? 818 return true; 819 #else 820 821 if (bytes < 2 * G) { 822 return true; 823 } 824 825 char* addr = reserve_memory(bytes, NULL); 826 827 if (addr != NULL) { 828 release_memory(addr, bytes); 829 } 830 831 return addr != NULL; 832 #endif // AMD64 833 } 834 835 //////////////////////////////////////////////////////////////////////////////// 836 // thread stack 837 838 // Minimum usable stack sizes required to get to user code. Space for 839 // HotSpot guard pages is added later. 840 size_t os::Posix::_compiler_thread_min_stack_allowed = 48 * K; 841 size_t os::Posix::_java_thread_min_stack_allowed = 48 * K; 842 #ifdef _LP64 843 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K; 844 #else 845 size_t os::Posix::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K; 846 #endif // _LP64 847 848 #ifndef AMD64 849 #ifdef __GNUC__ 850 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 851 #endif 852 #endif // AMD64 853 854 // return default stack size for thr_type 855 size_t os::Posix::default_stack_size(os::ThreadType thr_type) { 856 // default stack size (compiler thread needs larger stack) 857 #ifdef AMD64 858 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 859 #else 860 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 861 #endif // AMD64 862 return s; 863 } 864 865 866 // Java thread: 867 // 868 // Low memory addresses 869 // +------------------------+ 870 // | |\ Java thread created by VM does not have glibc 871 // | glibc guard page | - guard, attached Java thread usually has 872 // | |/ 1 glibc guard page. 873 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 874 // | |\ 875 // | HotSpot Guard Pages | - red, yellow and reserved pages 876 // | |/ 877 // +------------------------+ JavaThread::stack_reserved_zone_base() 878 // | |\ 879 // | Normal Stack | - 880 // | |/ 881 // P2 +------------------------+ Thread::stack_base() 882 // 883 // Non-Java thread: 884 // 885 // Low memory addresses 886 // +------------------------+ 887 // | |\ 888 // | glibc guard page | - usually 1 page 889 // | |/ 890 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 891 // | |\ 892 // | Normal Stack | - 893 // | |/ 894 // P2 +------------------------+ Thread::stack_base() 895 // 896 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 897 // pthread_attr_getstack() 898 899 static void current_stack_region(address * bottom, size_t * size) { 900 #ifdef __APPLE__ 901 pthread_t self = pthread_self(); 902 void *stacktop = pthread_get_stackaddr_np(self); 903 *size = pthread_get_stacksize_np(self); 904 // workaround for OS X 10.9.0 (Mavericks) 905 // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages 906 if (pthread_main_np() == 1) { 907 // At least on Mac OS 10.12 we have observed stack sizes not aligned 908 // to pages boundaries. This can be provoked by e.g. setrlimit() (ulimit -s xxxx in the 909 // shell). Apparently Mac OS actually rounds upwards to next multiple of page size, 910 // however, we round downwards here to be on the safe side. 911 *size = align_down(*size, getpagesize()); 912 913 if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) { 914 char kern_osrelease[256]; 915 size_t kern_osrelease_size = sizeof(kern_osrelease); 916 int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0); 917 if (ret == 0) { 918 // get the major number, atoi will ignore the minor amd micro portions of the version string 919 if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) { 920 *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize()); 921 } 922 } 923 } 924 } 925 *bottom = (address) stacktop - *size; 926 #elif defined(__OpenBSD__) 927 stack_t ss; 928 int rslt = pthread_stackseg_np(pthread_self(), &ss); 929 930 if (rslt != 0) 931 fatal("pthread_stackseg_np failed with error = %d", rslt); 932 933 *bottom = (address)((char *)ss.ss_sp - ss.ss_size); 934 *size = ss.ss_size; 935 #else 936 pthread_attr_t attr; 937 938 int rslt = pthread_attr_init(&attr); 939 940 // JVM needs to know exact stack location, abort if it fails 941 if (rslt != 0) 942 fatal("pthread_attr_init failed with error = %d", rslt); 943 944 rslt = pthread_attr_get_np(pthread_self(), &attr); 945 946 if (rslt != 0) 947 fatal("pthread_attr_get_np failed with error = %d", rslt); 948 949 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || 950 pthread_attr_getstacksize(&attr, size) != 0) { 951 fatal("Can not locate current stack attributes!"); 952 } 953 954 pthread_attr_destroy(&attr); 955 #endif 956 assert(os::current_stack_pointer() >= *bottom && 957 os::current_stack_pointer() < *bottom + *size, "just checking"); 958 } 959 960 address os::current_stack_base() { 961 address bottom; 962 size_t size; 963 current_stack_region(&bottom, &size); 964 return (bottom + size); 965 } 966 967 size_t os::current_stack_size() { 968 // stack size includes normal stack and HotSpot guard pages 969 address bottom; 970 size_t size; 971 current_stack_region(&bottom, &size); 972 return size; 973 } 974 975 ///////////////////////////////////////////////////////////////////////////// 976 // helper functions for fatal error handler 977 978 void os::print_context(outputStream *st, const void *context) { 979 if (context == NULL) return; 980 981 const ucontext_t *uc = (const ucontext_t*)context; 982 st->print_cr("Registers:"); 983 #ifdef AMD64 984 st->print( "RAX=" INTPTR_FORMAT, (intptr_t)uc->context_rax); 985 st->print(", RBX=" INTPTR_FORMAT, (intptr_t)uc->context_rbx); 986 st->print(", RCX=" INTPTR_FORMAT, (intptr_t)uc->context_rcx); 987 st->print(", RDX=" INTPTR_FORMAT, (intptr_t)uc->context_rdx); 988 st->cr(); 989 st->print( "RSP=" INTPTR_FORMAT, (intptr_t)uc->context_rsp); 990 st->print(", RBP=" INTPTR_FORMAT, (intptr_t)uc->context_rbp); 991 st->print(", RSI=" INTPTR_FORMAT, (intptr_t)uc->context_rsi); 992 st->print(", RDI=" INTPTR_FORMAT, (intptr_t)uc->context_rdi); 993 st->cr(); 994 st->print( "R8 =" INTPTR_FORMAT, (intptr_t)uc->context_r8); 995 st->print(", R9 =" INTPTR_FORMAT, (intptr_t)uc->context_r9); 996 st->print(", R10=" INTPTR_FORMAT, (intptr_t)uc->context_r10); 997 st->print(", R11=" INTPTR_FORMAT, (intptr_t)uc->context_r11); 998 st->cr(); 999 st->print( "R12=" INTPTR_FORMAT, (intptr_t)uc->context_r12); 1000 st->print(", R13=" INTPTR_FORMAT, (intptr_t)uc->context_r13); 1001 st->print(", R14=" INTPTR_FORMAT, (intptr_t)uc->context_r14); 1002 st->print(", R15=" INTPTR_FORMAT, (intptr_t)uc->context_r15); 1003 st->cr(); 1004 st->print( "RIP=" INTPTR_FORMAT, (intptr_t)uc->context_rip); 1005 st->print(", EFLAGS=" INTPTR_FORMAT, (intptr_t)uc->context_flags); 1006 st->print(", ERR=" INTPTR_FORMAT, (intptr_t)uc->context_err); 1007 st->cr(); 1008 st->print(" TRAPNO=" INTPTR_FORMAT, (intptr_t)uc->context_trapno); 1009 #else 1010 st->print( "EAX=" INTPTR_FORMAT, (intptr_t)uc->context_eax); 1011 st->print(", EBX=" INTPTR_FORMAT, (intptr_t)uc->context_ebx); 1012 st->print(", ECX=" INTPTR_FORMAT, (intptr_t)uc->context_ecx); 1013 st->print(", EDX=" INTPTR_FORMAT, (intptr_t)uc->context_edx); 1014 st->cr(); 1015 st->print( "ESP=" INTPTR_FORMAT, (intptr_t)uc->context_esp); 1016 st->print(", EBP=" INTPTR_FORMAT, (intptr_t)uc->context_ebp); 1017 st->print(", ESI=" INTPTR_FORMAT, (intptr_t)uc->context_esi); 1018 st->print(", EDI=" INTPTR_FORMAT, (intptr_t)uc->context_edi); 1019 st->cr(); 1020 st->print( "EIP=" INTPTR_FORMAT, (intptr_t)uc->context_eip); 1021 st->print(", EFLAGS=" INTPTR_FORMAT, (intptr_t)uc->context_eflags); 1022 #endif // AMD64 1023 st->cr(); 1024 st->cr(); 1025 1026 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); 1027 st->print_cr("Top of Stack: (sp=" INTPTR_FORMAT ")", (intptr_t)sp); 1028 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 1029 st->cr(); 1030 1031 // Note: it may be unsafe to inspect memory near pc. For example, pc may 1032 // point to garbage if entry point in an nmethod is corrupted. Leave 1033 // this at the end, and hope for the best. 1034 address pc = os::Bsd::ucontext_get_pc(uc); 1035 st->print_cr("Instructions: (pc=" INTPTR_FORMAT ")", (intptr_t)pc); 1036 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 1037 } 1038 1039 void os::print_register_info(outputStream *st, const void *context) { 1040 if (context == NULL) return; 1041 1042 const ucontext_t *uc = (const ucontext_t*)context; 1043 1044 st->print_cr("Register to memory mapping:"); 1045 st->cr(); 1046 1047 // this is horrendously verbose but the layout of the registers in the 1048 // context does not match how we defined our abstract Register set, so 1049 // we can't just iterate through the gregs area 1050 1051 // this is only for the "general purpose" registers 1052 1053 #ifdef AMD64 1054 st->print("RAX="); print_location(st, uc->context_rax); 1055 st->print("RBX="); print_location(st, uc->context_rbx); 1056 st->print("RCX="); print_location(st, uc->context_rcx); 1057 st->print("RDX="); print_location(st, uc->context_rdx); 1058 st->print("RSP="); print_location(st, uc->context_rsp); 1059 st->print("RBP="); print_location(st, uc->context_rbp); 1060 st->print("RSI="); print_location(st, uc->context_rsi); 1061 st->print("RDI="); print_location(st, uc->context_rdi); 1062 st->print("R8 ="); print_location(st, uc->context_r8); 1063 st->print("R9 ="); print_location(st, uc->context_r9); 1064 st->print("R10="); print_location(st, uc->context_r10); 1065 st->print("R11="); print_location(st, uc->context_r11); 1066 st->print("R12="); print_location(st, uc->context_r12); 1067 st->print("R13="); print_location(st, uc->context_r13); 1068 st->print("R14="); print_location(st, uc->context_r14); 1069 st->print("R15="); print_location(st, uc->context_r15); 1070 #else 1071 st->print("EAX="); print_location(st, uc->context_eax); 1072 st->print("EBX="); print_location(st, uc->context_ebx); 1073 st->print("ECX="); print_location(st, uc->context_ecx); 1074 st->print("EDX="); print_location(st, uc->context_edx); 1075 st->print("ESP="); print_location(st, uc->context_esp); 1076 st->print("EBP="); print_location(st, uc->context_ebp); 1077 st->print("ESI="); print_location(st, uc->context_esi); 1078 st->print("EDI="); print_location(st, uc->context_edi); 1079 #endif // AMD64 1080 1081 st->cr(); 1082 } 1083 1084 void os::setup_fpu() { 1085 #ifndef AMD64 1086 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 1087 __asm__ volatile ( "fldcw (%0)" : 1088 : "r" (fpu_cntrl) : "memory"); 1089 #endif // !AMD64 1090 } 1091 1092 #ifndef PRODUCT 1093 void os::verify_stack_alignment() { 1094 } 1095 #endif 1096 1097 int os::extra_bang_size_in_bytes() { 1098 // JDK-8050147 requires the full cache line bang for x86. 1099 return VM_Version::L1_line_size(); 1100 }