1 /*
2 * Copyright (c) 2003, 2020, 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 #if !defined(__APPLE__) && !defined(__NetBSD__)
27 #include <pthread.h>
28 # include <pthread_np.h> /* For pthread_attr_get_np */
29 #endif
30
31 // no precompiled headers
32 #include "jvm.h"
33 #include "assembler_zero.inline.hpp"
34 #include "classfile/classLoader.hpp"
35 #include "classfile/systemDictionary.hpp"
36 #include "classfile/vmSymbols.hpp"
37 #include "code/icBuffer.hpp"
38 #include "code/vtableStubs.hpp"
39 #include "interpreter/interpreter.hpp"
40 #include "memory/allocation.inline.hpp"
41 #include "nativeInst_zero.hpp"
42 #include "os_share_bsd.hpp"
43 #include "prims/jniFastGetField.hpp"
44 #include "prims/jvm_misc.hpp"
45 #include "runtime/arguments.hpp"
46 #include "runtime/extendedPC.hpp"
47 #include "runtime/frame.inline.hpp"
48 #include "runtime/interfaceSupport.inline.hpp"
49 #include "runtime/java.hpp"
50 #include "runtime/javaCalls.hpp"
51 #include "runtime/mutexLocker.hpp"
52 #include "runtime/osThread.hpp"
53 #include "runtime/sharedRuntime.hpp"
54 #include "runtime/stubRoutines.hpp"
55 #include "runtime/thread.inline.hpp"
56 #include "runtime/timer.hpp"
57 #include "utilities/events.hpp"
58 #include "utilities/vmError.hpp"
59
60 // See stubGenerator_zero.cpp
61 #include <setjmp.h>
62 extern sigjmp_buf* get_jmp_buf_for_continuation();
63
64 address os::current_stack_pointer() {
65 address dummy = (address) &dummy;
66 return dummy;
67 }
68
69 frame os::get_sender_for_C_frame(frame* fr) {
70 ShouldNotCallThis();
71 return frame();
72 }
73
74 frame os::current_frame() {
75 // The only thing that calls this is the stack printing code in
76 // VMError::report:
77 // - Step 110 (printing stack bounds) uses the sp in the frame
78 // to determine the amount of free space on the stack. We
79 // set the sp to a close approximation of the real value in
80 // order to allow this step to complete.
81 // - Step 120 (printing native stack) tries to walk the stack.
82 // The frame we create has a NULL pc, which is ignored as an
83 // invalid frame.
84 frame dummy = frame();
85 dummy.set_sp((intptr_t *) current_stack_pointer());
86 return dummy;
87 }
88
89 char* os::non_memory_address_word() {
90 // Must never look like an address returned by reserve_memory,
91 // even in its subfields (as defined by the CPU immediate fields,
92 // if the CPU splits constants across multiple instructions).
93 // This is the value for x86; works pretty well for PPC too.
94 return (char *) -1;
95 }
96
97 address os::Bsd::ucontext_get_pc(const ucontext_t* uc) {
98 ShouldNotCallThis();
99 return NULL;
100 }
101
102 void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) {
103 ShouldNotCallThis();
104 }
105
106 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
107 intptr_t** ret_sp,
108 intptr_t** ret_fp) {
109 ShouldNotCallThis();
110 return ExtendedPC();
111 }
112
113 frame os::fetch_frame_from_context(const void* ucVoid) {
114 ShouldNotCallThis();
115 return frame();
116 }
117
118 extern "C" JNIEXPORT int
119 JVM_handle_bsd_signal(int sig,
120 siginfo_t* info,
121 void* ucVoid,
122 int abort_if_unrecognized) {
123 ucontext_t* uc = (ucontext_t*) ucVoid;
124
125 Thread* t = Thread::current_or_null_safe();
126
127 SignalHandlerMark shm(t);
128
129 // handle SafeFetch faults
130 if (sig == SIGSEGV || sig == SIGBUS) {
131 sigjmp_buf* const pjb = get_jmp_buf_for_continuation();
132 if (pjb) {
133 siglongjmp(*pjb, 1);
134 }
135 }
136
137 // Note: it's not uncommon that JNI code uses signal/sigset to
138 // install then restore certain signal handler (e.g. to temporarily
139 // block SIGPIPE, or have a SIGILL handler when detecting CPU
140 // type). When that happens, JVM_handle_bsd_signal() might be
141 // invoked with junk info/ucVoid. To avoid unnecessary crash when
142 // libjsig is not preloaded, try handle signals that do not require
143 // siginfo/ucontext first.
144
145 if (sig == SIGPIPE || sig == SIGXFSZ) {
146 // allow chained handler to go first
147 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
148 return true;
149 } else {
150 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
151 return true;
152 }
153 }
154
155 JavaThread* thread = NULL;
156 VMThread* vmthread = NULL;
157 if (os::Bsd::signal_handlers_are_installed) {
158 if (t != NULL ){
159 if(t->is_Java_thread()) {
160 thread = (JavaThread*)t;
161 }
162 else if(t->is_VM_thread()){
163 vmthread = (VMThread *)t;
164 }
165 }
166 }
167
168 if (info != NULL && thread != NULL) {
169 // Handle ALL stack overflow variations here
170 if (sig == SIGSEGV || sig == SIGBUS) {
171 address addr = (address) info->si_addr;
172
173 // check if fault address is within thread stack
174 if (thread->is_in_full_stack(addr)) {
175 // stack overflow
176 if (thread->in_stack_yellow_reserved_zone(addr)) {
177 thread->disable_stack_yellow_reserved_zone();
178 ShouldNotCallThis();
179 }
180 else if (thread->in_stack_red_zone(addr)) {
181 thread->disable_stack_red_zone();
182 ShouldNotCallThis();
183 }
184 }
185 }
186
187 /*if (thread->thread_state() == _thread_in_Java) {
188 ShouldNotCallThis();
189 }
190 else*/ if ((thread->thread_state() == _thread_in_vm ||
191 thread->thread_state() == _thread_in_native) &&
192 sig == SIGBUS && thread->doing_unsafe_access()) {
193 ShouldNotCallThis();
194 }
195
196 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC
197 // kicks in and the heap gets shrunk before the field access.
198 /*if (sig == SIGSEGV || sig == SIGBUS) {
199 address addr = JNI_FastGetField::find_slowcase_pc(pc);
200 if (addr != (address)-1) {
201 stub = addr;
202 }
203 }*/
204 }
205
206 // signal-chaining
207 if (os::Bsd::chained_handler(sig, info, ucVoid)) {
208 return true;
209 }
210
211 if (!abort_if_unrecognized) {
212 // caller wants another chance, so give it to him
213 return false;
214 }
215
216 #ifndef PRODUCT
217 if (sig == SIGSEGV) {
218 fatal("\n#"
219 "\n# /--------------------\\"
220 "\n# | segmentation fault |"
221 "\n# \\---\\ /--------------/"
222 "\n# /"
223 "\n# [-] |\\_/| "
224 "\n# (+)=C |o o|__ "
225 "\n# | | =-*-=__\\ "
226 "\n# OOO c_c_(___)");
227 }
228 #endif // !PRODUCT
229
230 const char *fmt =
231 "caught unhandled signal " INT32_FORMAT " at address " PTR_FORMAT;
232 char buf[128];
233
234 sprintf(buf, fmt, sig, info->si_addr);
235 fatal(buf);
236 return false;
237 }
238
239 void os::Bsd::init_thread_fpu_state(void) {
240 // Nothing to do
241 }
242
243 bool os::is_allocatable(size_t bytes) {
244 #ifdef _LP64
245 return true;
246 #else
247 if (bytes < 2 * G) {
248 return true;
249 }
250
251 char* addr = reserve_memory(bytes, NULL);
252
253 if (addr != NULL) {
254 release_memory(addr, bytes);
255 }
256
257 return addr != NULL;
258 #endif // _LP64
259 }
260
261 ///////////////////////////////////////////////////////////////////////////////
262 // thread stack
263
264 size_t os::Posix::_compiler_thread_min_stack_allowed = 64 * K;
265 size_t os::Posix::_java_thread_min_stack_allowed = 64 * K;
266 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
267
268 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
269 #ifdef _LP64
270 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
271 #else
272 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
273 #endif // _LP64
274 return s;
275 }
276
277 static void current_stack_region(address *bottom, size_t *size) {
278 address stack_bottom;
279 address stack_top;
280 size_t stack_bytes;
281
282 #ifdef __APPLE__
283 pthread_t self = pthread_self();
284 stack_top = (address) pthread_get_stackaddr_np(self);
285 stack_bytes = pthread_get_stacksize_np(self);
286 stack_bottom = stack_top - stack_bytes;
287 #elif defined(__OpenBSD__)
288 stack_t ss;
289 int rslt = pthread_stackseg_np(pthread_self(), &ss);
290
291 if (rslt != 0)
292 fatal("pthread_stackseg_np failed with error = " INT32_FORMAT, rslt);
293
294 stack_top = (address) ss.ss_sp;
295 stack_bytes = ss.ss_size;
296 stack_bottom = stack_top - stack_bytes;
297 #else
298 pthread_attr_t attr;
299
300 int rslt = pthread_attr_init(&attr);
301
302 // JVM needs to know exact stack location, abort if it fails
303 if (rslt != 0)
304 fatal("pthread_attr_init failed with error = " INT32_FORMAT, rslt);
305
306 rslt = pthread_attr_get_np(pthread_self(), &attr);
307
308 if (rslt != 0)
309 fatal("pthread_attr_get_np failed with error = " INT32_FORMAT, rslt);
310
311 if (pthread_attr_getstackaddr(&attr, (void **) &stack_bottom) != 0 ||
312 pthread_attr_getstacksize(&attr, &stack_bytes) != 0) {
313 fatal("Can not locate current stack attributes!");
314 }
315
316 pthread_attr_destroy(&attr);
317
318 stack_top = stack_bottom + stack_bytes;
319 #endif
320
321 assert(os::current_stack_pointer() >= stack_bottom, "should do");
322 assert(os::current_stack_pointer() < stack_top, "should do");
323
324 *bottom = stack_bottom;
325 *size = stack_top - stack_bottom;
326 }
327
328 address os::current_stack_base() {
329 address bottom;
330 size_t size;
331 current_stack_region(&bottom, &size);
332 return bottom + size;
333 }
334
335 size_t os::current_stack_size() {
336 // stack size includes normal stack and HotSpot guard pages
337 address bottom;
338 size_t size;
339 current_stack_region(&bottom, &size);
340 return size;
341 }
342
343 /////////////////////////////////////////////////////////////////////////////
344 // helper functions for fatal error handler
345
346 void os::print_context(outputStream* st, const void* context) {
347 ShouldNotCallThis();
348 }
349
350 void os::print_register_info(outputStream *st, const void *context) {
351 ShouldNotCallThis();
352 }
353
354 /////////////////////////////////////////////////////////////////////////////
355 // Stubs for things that would be in bsd_zero.s if it existed.
356 // You probably want to disassemble these monkeys to check they're ok.
357
358 extern "C" {
359 int SpinPause() {
360 return 1;
361 }
362
363 void _Copy_conjoint_jshorts_atomic(const jshort* from, jshort* to, size_t count) {
364 if (from > to) {
365 const jshort *end = from + count;
366 while (from < end)
367 *(to++) = *(from++);
368 }
369 else if (from < to) {
370 const jshort *end = from;
371 from += count - 1;
372 to += count - 1;
373 while (from >= end)
374 *(to--) = *(from--);
375 }
376 }
377 void _Copy_conjoint_jints_atomic(const jint* from, jint* to, size_t count) {
378 if (from > to) {
379 const jint *end = from + count;
380 while (from < end)
381 *(to++) = *(from++);
382 }
383 else if (from < to) {
384 const jint *end = from;
385 from += count - 1;
386 to += count - 1;
387 while (from >= end)
388 *(to--) = *(from--);
389 }
390 }
391 void _Copy_conjoint_jlongs_atomic(const jlong* from, jlong* to, size_t count) {
392 if (from > to) {
393 const jlong *end = from + count;
394 while (from < end)
395 os::atomic_copy64(from++, to++);
396 }
397 else if (from < to) {
398 const jlong *end = from;
399 from += count - 1;
400 to += count - 1;
401 while (from >= end)
402 os::atomic_copy64(from--, to--);
403 }
404 }
405
406 void _Copy_arrayof_conjoint_bytes(const HeapWord* from,
407 HeapWord* to,
408 size_t count) {
409 memmove(to, from, count);
410 }
411 void _Copy_arrayof_conjoint_jshorts(const HeapWord* from,
412 HeapWord* to,
413 size_t count) {
414 memmove(to, from, count * 2);
415 }
416 void _Copy_arrayof_conjoint_jints(const HeapWord* from,
417 HeapWord* to,
418 size_t count) {
419 memmove(to, from, count * 4);
420 }
421 void _Copy_arrayof_conjoint_jlongs(const HeapWord* from,
422 HeapWord* to,
423 size_t count) {
424 memmove(to, from, count * 8);
425 }
426 };
427
428 /////////////////////////////////////////////////////////////////////////////
429 // Implementations of atomic operations not supported by processors.
430 // -- http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Atomic-Builtins.html
431
432 #ifndef _LP64
433 extern "C" {
434 long long unsigned int __sync_val_compare_and_swap_8(
435 volatile void *ptr,
436 long long unsigned int oldval,
437 long long unsigned int newval) {
438 ShouldNotCallThis();
439 }
440 };
441 #endif // !_LP64
442
443 #ifndef PRODUCT
444 void os::verify_stack_alignment() {
445 }
446 #endif
447
448 int os::extra_bang_size_in_bytes() {
449 // Zero does not require an additional stack bang.
450 return 0;
451 }