1 /* 2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. 3 * Copyright 2007, 2008, 2009, 2010 Red Hat, Inc. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 // no precompiled headers 27 #include "assembler_zero.inline.hpp" 28 #include "classfile/classLoader.hpp" 29 #include "classfile/systemDictionary.hpp" 30 #include "classfile/vmSymbols.hpp" 31 #include "code/icBuffer.hpp" 32 #include "code/vtableStubs.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "jvm_linux.h" 35 #include "memory/allocation.inline.hpp" 36 #include "mutex_linux.inline.hpp" 37 #include "nativeInst_zero.hpp" 38 #include "os_share_linux.hpp" 39 #include "prims/jniFastGetField.hpp" 40 #include "prims/jvm.h" 41 #include "prims/jvm_misc.hpp" 42 #include "runtime/arguments.hpp" 43 #include "runtime/extendedPC.hpp" 44 #include "runtime/frame.inline.hpp" 45 #include "runtime/interfaceSupport.hpp" 46 #include "runtime/java.hpp" 47 #include "runtime/javaCalls.hpp" 48 #include "runtime/mutexLocker.hpp" 49 #include "runtime/osThread.hpp" 50 #include "runtime/sharedRuntime.hpp" 51 #include "runtime/stubRoutines.hpp" 52 #include "runtime/thread.inline.hpp" 53 #include "runtime/timer.hpp" 54 #include "utilities/events.hpp" 55 #include "utilities/vmError.hpp" 56 57 address os::current_stack_pointer() { 58 address dummy = (address) &dummy; 59 return dummy; 60 } 61 62 frame os::get_sender_for_C_frame(frame* fr) { 63 ShouldNotCallThis(); 64 } 65 66 frame os::current_frame() { 67 // The only thing that calls this is the stack printing code in 68 // VMError::report: 69 // - Step 110 (printing stack bounds) uses the sp in the frame 70 // to determine the amount of free space on the stack. We 71 // set the sp to a close approximation of the real value in 72 // order to allow this step to complete. 73 // - Step 120 (printing native stack) tries to walk the stack. 74 // The frame we create has a NULL pc, which is ignored as an 75 // invalid frame. 76 frame dummy = frame(); 77 dummy.set_sp((intptr_t *) current_stack_pointer()); 78 return dummy; 79 } 80 81 char* os::non_memory_address_word() { 82 // Must never look like an address returned by reserve_memory, 83 // even in its subfields (as defined by the CPU immediate fields, 84 // if the CPU splits constants across multiple instructions). 85 #ifdef SPARC 86 // On SPARC, 0 != %hi(any real address), because there is no 87 // allocation in the first 1Kb of the virtual address space. 88 return (char *) 0; 89 #else 90 // This is the value for x86; works pretty well for PPC too. 91 return (char *) -1; 92 #endif // SPARC 93 } 94 95 void os::initialize_thread(Thread * thr){ 96 // Nothing to do. 97 } 98 99 address os::Linux::ucontext_get_pc(ucontext_t* uc) { 100 ShouldNotCallThis(); 101 } 102 103 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) { 104 ShouldNotCallThis(); 105 } 106 107 ExtendedPC os::fetch_frame_from_context(void* ucVoid, 108 intptr_t** ret_sp, 109 intptr_t** ret_fp) { 110 ShouldNotCallThis(); 111 } 112 113 frame os::fetch_frame_from_context(void* ucVoid) { 114 ShouldNotCallThis(); 115 } 116 117 extern "C" JNIEXPORT int 118 JVM_handle_linux_signal(int sig, 119 siginfo_t* info, 120 void* ucVoid, 121 int abort_if_unrecognized) { 122 ucontext_t* uc = (ucontext_t*) ucVoid; 123 124 Thread* t = ThreadLocalStorage::get_thread_slow(); 125 126 SignalHandlerMark shm(t); 127 128 // Note: it's not uncommon that JNI code uses signal/sigset to 129 // install then restore certain signal handler (e.g. to temporarily 130 // block SIGPIPE, or have a SIGILL handler when detecting CPU 131 // type). When that happens, JVM_handle_linux_signal() might be 132 // invoked with junk info/ucVoid. To avoid unnecessary crash when 133 // libjsig is not preloaded, try handle signals that do not require 134 // siginfo/ucontext first. 135 136 if (sig == SIGPIPE || sig == SIGXFSZ) { 137 // allow chained handler to go first 138 if (os::Linux::chained_handler(sig, info, ucVoid)) { 139 return true; 140 } else { 141 if (PrintMiscellaneous && (WizardMode || Verbose)) { 142 char buf[64]; 143 warning("Ignoring %s - see bugs 4229104 or 646499219", 144 os::exception_name(sig, buf, sizeof(buf))); 145 } 146 return true; 147 } 148 } 149 150 JavaThread* thread = NULL; 151 VMThread* vmthread = NULL; 152 if (os::Linux::signal_handlers_are_installed) { 153 if (t != NULL ){ 154 if(t->is_Java_thread()) { 155 thread = (JavaThread*)t; 156 } 157 else if(t->is_VM_thread()){ 158 vmthread = (VMThread *)t; 159 } 160 } 161 } 162 163 if (info != NULL && thread != NULL) { 164 // Handle ALL stack overflow variations here 165 if (sig == SIGSEGV) { 166 address addr = (address) info->si_addr; 167 168 // check if fault address is within thread stack 169 if (addr < thread->stack_base() && 170 addr >= thread->stack_base() - thread->stack_size()) { 171 // stack overflow 172 if (thread->in_stack_yellow_zone(addr)) { 173 thread->disable_stack_yellow_zone(); 174 ShouldNotCallThis(); 175 } 176 else if (thread->in_stack_red_zone(addr)) { 177 thread->disable_stack_red_zone(); 178 ShouldNotCallThis(); 179 } 180 else { 181 // Accessing stack address below sp may cause SEGV if 182 // current thread has MAP_GROWSDOWN stack. This should 183 // only happen when current thread was created by user 184 // code with MAP_GROWSDOWN flag and then attached to VM. 185 // See notes in os_linux.cpp. 186 if (thread->osthread()->expanding_stack() == 0) { 187 thread->osthread()->set_expanding_stack(); 188 if (os::Linux::manually_expand_stack(thread, addr)) { 189 thread->osthread()->clear_expanding_stack(); 190 return true; 191 } 192 thread->osthread()->clear_expanding_stack(); 193 } 194 else { 195 fatal("recursive segv. expanding stack."); 196 } 197 } 198 } 199 } 200 201 /*if (thread->thread_state() == _thread_in_Java) { 202 ShouldNotCallThis(); 203 } 204 else*/ if (thread->thread_state() == _thread_in_vm && 205 sig == SIGBUS && thread->doing_unsafe_access()) { 206 ShouldNotCallThis(); 207 } 208 209 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC 210 // kicks in and the heap gets shrunk before the field access. 211 /*if (sig == SIGSEGV || sig == SIGBUS) { 212 address addr = JNI_FastGetField::find_slowcase_pc(pc); 213 if (addr != (address)-1) { 214 stub = addr; 215 } 216 }*/ 217 218 // Check to see if we caught the safepoint code in the process 219 // of write protecting the memory serialization page. It write 220 // enables the page immediately after protecting it so we can 221 // just return to retry the write. 222 if (sig == SIGSEGV && 223 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 224 // Block current thread until permission is restored. 225 os::block_on_serialize_page_trap(); 226 return true; 227 } 228 } 229 230 // signal-chaining 231 if (os::Linux::chained_handler(sig, info, ucVoid)) { 232 return true; 233 } 234 235 if (!abort_if_unrecognized) { 236 // caller wants another chance, so give it to him 237 return false; 238 } 239 240 #ifndef PRODUCT 241 if (sig == SIGSEGV) { 242 fatal("\n#" 243 "\n# /--------------------\\" 244 "\n# | segmentation fault |" 245 "\n# \\---\\ /--------------/" 246 "\n# /" 247 "\n# [-] |\\_/| " 248 "\n# (+)=C |o o|__ " 249 "\n# | | =-*-=__\\ " 250 "\n# OOO c_c_(___)"); 251 } 252 #endif // !PRODUCT 253 254 const char *fmt = "caught unhandled signal %d"; 255 char buf[64]; 256 257 sprintf(buf, fmt, sig); 258 fatal(buf); 259 } 260 261 void os::Linux::init_thread_fpu_state(void) { 262 // Nothing to do 263 } 264 265 int os::Linux::get_fpu_control_word() { 266 ShouldNotCallThis(); 267 } 268 269 void os::Linux::set_fpu_control_word(int fpu) { 270 ShouldNotCallThis(); 271 } 272 273 bool os::is_allocatable(size_t bytes) { 274 #ifdef _LP64 275 return true; 276 #else 277 if (bytes < 2 * G) { 278 return true; 279 } 280 281 char* addr = reserve_memory(bytes, NULL); 282 283 if (addr != NULL) { 284 release_memory(addr, bytes); 285 } 286 287 return addr != NULL; 288 #endif // _LP64 289 } 290 291 /////////////////////////////////////////////////////////////////////////////// 292 // thread stack 293 294 size_t os::Linux::min_stack_allowed = 64 * K; 295 296 bool os::Linux::supports_variable_stack_size() { 297 return true; 298 } 299 300 size_t os::Linux::default_stack_size(os::ThreadType thr_type) { 301 #ifdef _LP64 302 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 303 #else 304 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 305 #endif // _LP64 306 return s; 307 } 308 309 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 310 // Only enable glibc guard pages for non-Java threads 311 // (Java threads have HotSpot guard pages) 312 return (thr_type == java_thread ? 0 : page_size()); 313 } 314 315 static void current_stack_region(address *bottom, size_t *size) { 316 pthread_attr_t attr; 317 int res = pthread_getattr_np(pthread_self(), &attr); 318 if (res != 0) { 319 if (res == ENOMEM) { 320 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); 321 } 322 else { 323 fatal(err_msg("pthread_getattr_np failed with errno = %d", res)); 324 } 325 } 326 327 address stack_bottom; 328 size_t stack_bytes; 329 res = pthread_attr_getstack(&attr, (void **) &stack_bottom, &stack_bytes); 330 if (res != 0) { 331 fatal(err_msg("pthread_attr_getstack failed with errno = %d", res)); 332 } 333 address stack_top = stack_bottom + stack_bytes; 334 335 // The block of memory returned by pthread_attr_getstack() includes 336 // guard pages where present. We need to trim these off. 337 size_t page_bytes = os::Linux::page_size(); 338 assert(((intptr_t) stack_bottom & (page_bytes - 1)) == 0, "unaligned stack"); 339 340 size_t guard_bytes; 341 res = pthread_attr_getguardsize(&attr, &guard_bytes); 342 if (res != 0) { 343 fatal(err_msg("pthread_attr_getguardsize failed with errno = %d", res)); 344 } 345 int guard_pages = align_size_up(guard_bytes, page_bytes) / page_bytes; 346 assert(guard_bytes == guard_pages * page_bytes, "unaligned guard"); 347 348 #ifdef IA64 349 // IA64 has two stacks sharing the same area of memory, a normal 350 // stack growing downwards and a register stack growing upwards. 351 // Guard pages, if present, are in the centre. This code splits 352 // the stack in two even without guard pages, though in theory 353 // there's nothing to stop us allocating more to the normal stack 354 // or more to the register stack if one or the other were found 355 // to grow faster. 356 int total_pages = align_size_down(stack_bytes, page_bytes) / page_bytes; 357 stack_bottom += (total_pages - guard_pages) / 2 * page_bytes; 358 #endif // IA64 359 360 stack_bottom += guard_bytes; 361 362 pthread_attr_destroy(&attr); 363 364 // The initial thread has a growable stack, and the size reported 365 // by pthread_attr_getstack is the maximum size it could possibly 366 // be given what currently mapped. This can be huge, so we cap it. 367 if (os::Linux::is_initial_thread()) { 368 stack_bytes = stack_top - stack_bottom; 369 370 if (stack_bytes > JavaThread::stack_size_at_create()) 371 stack_bytes = JavaThread::stack_size_at_create(); 372 373 stack_bottom = stack_top - stack_bytes; 374 } 375 376 assert(os::current_stack_pointer() >= stack_bottom, "should do"); 377 assert(os::current_stack_pointer() < stack_top, "should do"); 378 379 *bottom = stack_bottom; 380 *size = stack_top - stack_bottom; 381 } 382 383 address os::current_stack_base() { 384 address bottom; 385 size_t size; 386 current_stack_region(&bottom, &size); 387 return bottom + size; 388 } 389 390 size_t os::current_stack_size() { 391 // stack size includes normal stack and HotSpot guard pages 392 address bottom; 393 size_t size; 394 current_stack_region(&bottom, &size); 395 return size; 396 } 397 398 ///////////////////////////////////////////////////////////////////////////// 399 // helper functions for fatal error handler 400 401 void os::print_context(outputStream* st, void* context) { 402 ShouldNotCallThis(); 403 } 404 405 void os::print_register_info(outputStream *st, void *context) { 406 ShouldNotCallThis(); 407 } 408 409 ///////////////////////////////////////////////////////////////////////////// 410 // Stubs for things that would be in linux_zero.s if it existed. 411 // You probably want to disassemble these monkeys to check they're ok. 412 413 extern "C" { 414 int SpinPause() { 415 } 416 417 418 void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) { 419 if (from > to) { 420 jshort *end = from + count; 421 while (from < end) 422 *(to++) = *(from++); 423 } 424 else if (from < to) { 425 jshort *end = from; 426 from += count - 1; 427 to += count - 1; 428 while (from >= end) 429 *(to--) = *(from--); 430 } 431 } 432 void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) { 433 if (from > to) { 434 jint *end = from + count; 435 while (from < end) 436 *(to++) = *(from++); 437 } 438 else if (from < to) { 439 jint *end = from; 440 from += count - 1; 441 to += count - 1; 442 while (from >= end) 443 *(to--) = *(from--); 444 } 445 } 446 void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) { 447 if (from > to) { 448 jlong *end = from + count; 449 while (from < end) 450 os::atomic_copy64(from++, to++); 451 } 452 else if (from < to) { 453 jlong *end = from; 454 from += count - 1; 455 to += count - 1; 456 while (from >= end) 457 os::atomic_copy64(from--, to--); 458 } 459 } 460 461 void _Copy_arrayof_conjoint_bytes(HeapWord* from, 462 HeapWord* to, 463 size_t count) { 464 memmove(to, from, count); 465 } 466 void _Copy_arrayof_conjoint_jshorts(HeapWord* from, 467 HeapWord* to, 468 size_t count) { 469 memmove(to, from, count * 2); 470 } 471 void _Copy_arrayof_conjoint_jints(HeapWord* from, 472 HeapWord* to, 473 size_t count) { 474 memmove(to, from, count * 4); 475 } 476 void _Copy_arrayof_conjoint_jlongs(HeapWord* from, 477 HeapWord* to, 478 size_t count) { 479 memmove(to, from, count * 8); 480 } 481 }; 482 483 ///////////////////////////////////////////////////////////////////////////// 484 // Implementations of atomic operations not supported by processors. 485 // -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html 486 487 #ifndef _LP64 488 extern "C" { 489 long long unsigned int __sync_val_compare_and_swap_8( 490 volatile void *ptr, 491 long long unsigned int oldval, 492 long long unsigned int newval) { 493 ShouldNotCallThis(); 494 } 495 }; 496 #endif // !_LP64 497 498 #ifndef PRODUCT 499 void os::verify_stack_alignment() { 500 } 501 #endif 502 503 int os::extra_bang_size_in_bytes() { 504 // Zero does not require an additional stack banging. 505 return 0; 506 }