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 // return the address of the current function 59 return (address)__builtin_frame_address(0); 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 ExtendedPC os::fetch_frame_from_context(void* ucVoid, 104 intptr_t** ret_sp, 105 intptr_t** ret_fp) { 106 ShouldNotCallThis(); 107 } 108 109 frame os::fetch_frame_from_context(void* ucVoid) { 110 ShouldNotCallThis(); 111 } 112 113 extern "C" JNIEXPORT int 114 JVM_handle_linux_signal(int sig, 115 siginfo_t* info, 116 void* ucVoid, 117 int abort_if_unrecognized) { 118 ucontext_t* uc = (ucontext_t*) ucVoid; 119 120 Thread* t = ThreadLocalStorage::get_thread_slow(); 121 122 SignalHandlerMark shm(t); 123 124 // Note: it's not uncommon that JNI code uses signal/sigset to 125 // install then restore certain signal handler (e.g. to temporarily 126 // block SIGPIPE, or have a SIGILL handler when detecting CPU 127 // type). When that happens, JVM_handle_linux_signal() might be 128 // invoked with junk info/ucVoid. To avoid unnecessary crash when 129 // libjsig is not preloaded, try handle signals that do not require 130 // siginfo/ucontext first. 131 132 if (sig == SIGPIPE || sig == SIGXFSZ) { 133 // allow chained handler to go first 134 if (os::Linux::chained_handler(sig, info, ucVoid)) { 135 return true; 136 } else { 137 if (PrintMiscellaneous && (WizardMode || Verbose)) { 138 char buf[64]; 139 warning("Ignoring %s - see bugs 4229104 or 646499219", 140 os::exception_name(sig, buf, sizeof(buf))); 141 } 142 return true; 143 } 144 } 145 146 JavaThread* thread = NULL; 147 VMThread* vmthread = NULL; 148 if (os::Linux::signal_handlers_are_installed) { 149 if (t != NULL ){ 150 if(t->is_Java_thread()) { 151 thread = (JavaThread*)t; 152 } 153 else if(t->is_VM_thread()){ 154 vmthread = (VMThread *)t; 155 } 156 } 157 } 158 159 if (info != NULL && thread != NULL) { 160 // Handle ALL stack overflow variations here 161 if (sig == SIGSEGV) { 162 address addr = (address) info->si_addr; 163 164 // check if fault address is within thread stack 165 if (addr < thread->stack_base() && 166 addr >= thread->stack_base() - thread->stack_size()) { 167 // stack overflow 168 if (thread->in_stack_yellow_zone(addr)) { 169 thread->disable_stack_yellow_zone(); 170 ShouldNotCallThis(); 171 } 172 else if (thread->in_stack_red_zone(addr)) { 173 thread->disable_stack_red_zone(); 174 ShouldNotCallThis(); 175 } 176 else { 177 // Accessing stack address below sp may cause SEGV if 178 // current thread has MAP_GROWSDOWN stack. This should 179 // only happen when current thread was created by user 180 // code with MAP_GROWSDOWN flag and then attached to VM. 181 // See notes in os_linux.cpp. 182 if (thread->osthread()->expanding_stack() == 0) { 183 thread->osthread()->set_expanding_stack(); 184 if (os::Linux::manually_expand_stack(thread, addr)) { 185 thread->osthread()->clear_expanding_stack(); 186 return true; 187 } 188 thread->osthread()->clear_expanding_stack(); 189 } 190 else { 191 fatal("recursive segv. expanding stack."); 192 } 193 } 194 } 195 } 196 197 /*if (thread->thread_state() == _thread_in_Java) { 198 ShouldNotCallThis(); 199 } 200 else*/ if (thread->thread_state() == _thread_in_vm && 201 sig == SIGBUS && thread->doing_unsafe_access()) { 202 ShouldNotCallThis(); 203 } 204 205 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC 206 // kicks in and the heap gets shrunk before the field access. 207 /*if (sig == SIGSEGV || sig == SIGBUS) { 208 address addr = JNI_FastGetField::find_slowcase_pc(pc); 209 if (addr != (address)-1) { 210 stub = addr; 211 } 212 }*/ 213 214 // Check to see if we caught the safepoint code in the process 215 // of write protecting the memory serialization page. It write 216 // enables the page immediately after protecting it so we can 217 // just return to retry the write. 218 if (sig == SIGSEGV && 219 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 220 // Block current thread until permission is restored. 221 os::block_on_serialize_page_trap(); 222 return true; 223 } 224 } 225 226 // signal-chaining 227 if (os::Linux::chained_handler(sig, info, ucVoid)) { 228 return true; 229 } 230 231 if (!abort_if_unrecognized) { 232 // caller wants another chance, so give it to him 233 return false; 234 } 235 236 #ifndef PRODUCT 237 if (sig == SIGSEGV) { 238 fatal("\n#" 239 "\n# /--------------------\\" 240 "\n# | segmentation fault |" 241 "\n# \\---\\ /--------------/" 242 "\n# /" 243 "\n# [-] |\\_/| " 244 "\n# (+)=C |o o|__ " 245 "\n# | | =-*-=__\\ " 246 "\n# OOO c_c_(___)"); 247 } 248 #endif // !PRODUCT 249 250 const char *fmt = "caught unhandled signal %d"; 251 char buf[64]; 252 253 sprintf(buf, fmt, sig); 254 fatal(buf); 255 } 256 257 void os::Linux::init_thread_fpu_state(void) { 258 // Nothing to do 259 } 260 261 int os::Linux::get_fpu_control_word() { 262 ShouldNotCallThis(); 263 } 264 265 void os::Linux::set_fpu_control_word(int fpu) { 266 ShouldNotCallThis(); 267 } 268 269 bool os::is_allocatable(size_t bytes) { 270 #ifdef _LP64 271 return true; 272 #else 273 if (bytes < 2 * G) { 274 return true; 275 } 276 277 char* addr = reserve_memory(bytes, NULL); 278 279 if (addr != NULL) { 280 release_memory(addr, bytes); 281 } 282 283 return addr != NULL; 284 #endif // _LP64 285 } 286 287 /////////////////////////////////////////////////////////////////////////////// 288 // thread stack 289 290 size_t os::Linux::min_stack_allowed = 64 * K; 291 292 bool os::Linux::supports_variable_stack_size() { 293 return true; 294 } 295 296 size_t os::Linux::default_stack_size(os::ThreadType thr_type) { 297 #ifdef _LP64 298 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 299 #else 300 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 301 #endif // _LP64 302 return s; 303 } 304 305 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 306 // Only enable glibc guard pages for non-Java threads 307 // (Java threads have HotSpot guard pages) 308 return (thr_type == java_thread ? 0 : page_size()); 309 } 310 311 static void current_stack_region(address *bottom, size_t *size) { 312 pthread_attr_t attr; 313 int res = pthread_getattr_np(pthread_self(), &attr); 314 if (res != 0) { 315 if (res == ENOMEM) { 316 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); 317 } 318 else { 319 fatal(err_msg("pthread_getattr_np failed with errno = %d", res)); 320 } 321 } 322 323 address stack_bottom; 324 size_t stack_bytes; 325 res = pthread_attr_getstack(&attr, (void **) &stack_bottom, &stack_bytes); 326 if (res != 0) { 327 fatal(err_msg("pthread_attr_getstack failed with errno = %d", res)); 328 } 329 address stack_top = stack_bottom + stack_bytes; 330 331 // The block of memory returned by pthread_attr_getstack() includes 332 // guard pages where present. We need to trim these off. 333 size_t page_bytes = os::Linux::page_size(); 334 assert(((intptr_t) stack_bottom & (page_bytes - 1)) == 0, "unaligned stack"); 335 336 size_t guard_bytes; 337 res = pthread_attr_getguardsize(&attr, &guard_bytes); 338 if (res != 0) { 339 fatal(err_msg("pthread_attr_getguardsize failed with errno = %d", res)); 340 } 341 int guard_pages = align_size_up(guard_bytes, page_bytes) / page_bytes; 342 assert(guard_bytes == guard_pages * page_bytes, "unaligned guard"); 343 344 #ifdef IA64 345 // IA64 has two stacks sharing the same area of memory, a normal 346 // stack growing downwards and a register stack growing upwards. 347 // Guard pages, if present, are in the centre. This code splits 348 // the stack in two even without guard pages, though in theory 349 // there's nothing to stop us allocating more to the normal stack 350 // or more to the register stack if one or the other were found 351 // to grow faster. 352 int total_pages = align_size_down(stack_bytes, page_bytes) / page_bytes; 353 stack_bottom += (total_pages - guard_pages) / 2 * page_bytes; 354 #endif // IA64 355 356 stack_bottom += guard_bytes; 357 358 pthread_attr_destroy(&attr); 359 360 // The initial thread has a growable stack, and the size reported 361 // by pthread_attr_getstack is the maximum size it could possibly 362 // be given what currently mapped. This can be huge, so we cap it. 363 if (os::Linux::is_initial_thread()) { 364 stack_bytes = stack_top - stack_bottom; 365 366 if (stack_bytes > JavaThread::stack_size_at_create()) 367 stack_bytes = JavaThread::stack_size_at_create(); 368 369 stack_bottom = stack_top - stack_bytes; 370 } 371 372 assert(os::current_stack_pointer() >= stack_bottom, "should do"); 373 assert(os::current_stack_pointer() < stack_top, "should do"); 374 375 *bottom = stack_bottom; 376 *size = stack_top - stack_bottom; 377 } 378 379 address os::current_stack_base() { 380 address bottom; 381 size_t size; 382 current_stack_region(&bottom, &size); 383 return bottom + size; 384 } 385 386 size_t os::current_stack_size() { 387 // stack size includes normal stack and HotSpot guard pages 388 address bottom; 389 size_t size; 390 current_stack_region(&bottom, &size); 391 return size; 392 } 393 394 ///////////////////////////////////////////////////////////////////////////// 395 // helper functions for fatal error handler 396 397 void os::print_context(outputStream* st, void* context) { 398 ShouldNotCallThis(); 399 } 400 401 void os::print_register_info(outputStream *st, void *context) { 402 ShouldNotCallThis(); 403 } 404 405 ///////////////////////////////////////////////////////////////////////////// 406 // Stubs for things that would be in linux_zero.s if it existed. 407 // You probably want to disassemble these monkeys to check they're ok. 408 409 extern "C" { 410 int SpinPause() { 411 } 412 413 414 void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) { 415 if (from > to) { 416 jshort *end = from + count; 417 while (from < end) 418 *(to++) = *(from++); 419 } 420 else if (from < to) { 421 jshort *end = from; 422 from += count - 1; 423 to += count - 1; 424 while (from >= end) 425 *(to--) = *(from--); 426 } 427 } 428 void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) { 429 if (from > to) { 430 jint *end = from + count; 431 while (from < end) 432 *(to++) = *(from++); 433 } 434 else if (from < to) { 435 jint *end = from; 436 from += count - 1; 437 to += count - 1; 438 while (from >= end) 439 *(to--) = *(from--); 440 } 441 } 442 void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) { 443 if (from > to) { 444 jlong *end = from + count; 445 while (from < end) 446 os::atomic_copy64(from++, to++); 447 } 448 else if (from < to) { 449 jlong *end = from; 450 from += count - 1; 451 to += count - 1; 452 while (from >= end) 453 os::atomic_copy64(from--, to--); 454 } 455 } 456 457 void _Copy_arrayof_conjoint_bytes(HeapWord* from, 458 HeapWord* to, 459 size_t count) { 460 memmove(to, from, count); 461 } 462 void _Copy_arrayof_conjoint_jshorts(HeapWord* from, 463 HeapWord* to, 464 size_t count) { 465 memmove(to, from, count * 2); 466 } 467 void _Copy_arrayof_conjoint_jints(HeapWord* from, 468 HeapWord* to, 469 size_t count) { 470 memmove(to, from, count * 4); 471 } 472 void _Copy_arrayof_conjoint_jlongs(HeapWord* from, 473 HeapWord* to, 474 size_t count) { 475 memmove(to, from, count * 8); 476 } 477 }; 478 479 ///////////////////////////////////////////////////////////////////////////// 480 // Implementations of atomic operations not supported by processors. 481 // -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html 482 483 #ifndef _LP64 484 extern "C" { 485 long long unsigned int __sync_val_compare_and_swap_8( 486 volatile void *ptr, 487 long long unsigned int oldval, 488 long long unsigned int newval) { 489 ShouldNotCallThis(); 490 } 491 }; 492 #endif // !_LP64 493 494 #ifndef PRODUCT 495 void os::verify_stack_alignment() { 496 } 497 #endif