1 /*
2 * Copyright (c) 2008, 2018, 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 "assembler_arm.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 "memory/allocation.inline.hpp"
35 #include "nativeInst_arm.hpp"
36 #include "os_share_linux.hpp"
37 #include "prims/jniFastGetField.hpp"
38 #include "prims/jvm_misc.hpp"
39 #include "runtime/arguments.hpp"
40 #include "runtime/extendedPC.hpp"
41 #include "runtime/frame.inline.hpp"
42 #include "runtime/interfaceSupport.inline.hpp"
43 #include "runtime/java.hpp"
44 #include "runtime/javaCalls.hpp"
45 #include "runtime/mutexLocker.hpp"
46 #include "runtime/osThread.hpp"
47 #include "runtime/sharedRuntime.hpp"
48 #include "runtime/stubRoutines.hpp"
49 #include "runtime/timer.hpp"
50 #include "utilities/debug.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/vmError.hpp"
53
54 // put OS-includes here
55 # include <sys/types.h>
56 # include <sys/mman.h>
57 # include <pthread.h>
58 # include <signal.h>
59 # include <errno.h>
60 # include <dlfcn.h>
61 # include <stdlib.h>
62 # include <stdio.h>
63 # include <unistd.h>
64 # include <sys/resource.h>
65 # include <pthread.h>
66 # include <sys/stat.h>
67 # include <sys/time.h>
68 # include <sys/utsname.h>
69 # include <sys/socket.h>
70 # include <sys/wait.h>
71 # include <pwd.h>
72 # include <poll.h>
73 # include <ucontext.h>
74 # include <fpu_control.h>
75 # include <asm/ptrace.h>
76
77 #define SPELL_REG_SP "sp"
78
79 // Don't #define SPELL_REG_FP for thumb because it is not safe to use, so this makes sure we never fetch it.
80 #ifndef __thumb__
81 #define SPELL_REG_FP "fp"
82 #endif
83
84 address os::current_stack_pointer() {
85 register address sp __asm__ (SPELL_REG_SP);
86 return sp;
87 }
88
89 char* os::non_memory_address_word() {
90 // Must never look like an address returned by reserve_memory
91 return (char*) -1;
92 }
93
94
95 #if NGREG == 16
96 // These definitions are based on the observation that until
97 // the certain version of GCC mcontext_t was defined as
98 // a structure containing gregs[NGREG] array with 16 elements.
99 // In later GCC versions mcontext_t was redefined as struct sigcontext,
100 // along with NGREG constant changed to 18.
101 #define arm_pc gregs[15]
102 #define arm_sp gregs[13]
103 #define arm_fp gregs[11]
104 #define arm_r0 gregs[0]
105 #endif
106
107 #define ARM_REGS_IN_CONTEXT 16
108
109
110 address os::Linux::ucontext_get_pc(const ucontext_t* uc) {
111 return (address)uc->uc_mcontext.arm_pc;
112 }
113
114 void os::Linux::ucontext_set_pc(ucontext_t* uc, address pc) {
115 uc->uc_mcontext.arm_pc = (uintx)pc;
116 }
117
118 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t* uc) {
119 return (intptr_t*)uc->uc_mcontext.arm_sp;
120 }
121
122 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t* uc) {
123 return (intptr_t*)uc->uc_mcontext.arm_fp;
124 }
125
126 bool is_safe_for_fp(address pc) {
127 #ifdef __thumb__
128 if (CodeCache::find_blob(pc) != NULL) {
129 return true;
130 }
131 // For thumb C frames, given an fp we have no idea how to access the frame contents.
132 return false;
133 #else
134 // Calling os::address_is_in_vm() here leads to a dladdr call. Calling any libc
135 // function during os::get_native_stack() can result in a deadlock if JFR is
136 // enabled. For now, be more lenient and allow all pc's. There are other
137 // frame sanity checks in shared code, and to date they have been sufficient
138 // for other platforms.
139 //return os::address_is_in_vm(pc);
140 return true;
141 #endif
142 }
143
144 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
145 // is currently interrupted by SIGPROF.
146 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
147 // frames. Currently we don't do that on Linux, so it's the same as
148 // os::fetch_frame_from_context().
149 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
150 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
151
152 assert(thread != NULL, "just checking");
153 assert(ret_sp != NULL, "just checking");
154 assert(ret_fp != NULL, "just checking");
155
156 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
157 }
158
159 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
160 intptr_t** ret_sp, intptr_t** ret_fp) {
161
162 ExtendedPC epc;
163 const ucontext_t* uc = (const ucontext_t*)ucVoid;
164
165 if (uc != NULL) {
166 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
167 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
168 if (ret_fp) {
169 intptr_t* fp = os::Linux::ucontext_get_fp(uc);
170 #ifndef __thumb__
171 if (CodeCache::find_blob(epc.pc()) == NULL) {
172 // It's a C frame. We need to adjust the fp.
173 fp += os::C_frame_offset;
174 }
175 #endif
176 // Clear FP when stack walking is dangerous so that
177 // the frame created will not be walked.
178 // However, ensure FP is set correctly when reliable and
179 // potentially necessary.
180 if (!is_safe_for_fp(epc.pc())) {
181 // FP unreliable
182 fp = (intptr_t *)NULL;
183 }
184 *ret_fp = fp;
185 }
186 } else {
187 // construct empty ExtendedPC for return value checking
188 epc = ExtendedPC(NULL);
189 if (ret_sp) *ret_sp = (intptr_t *)NULL;
190 if (ret_fp) *ret_fp = (intptr_t *)NULL;
191 }
192
193 return epc;
194 }
195
196 frame os::fetch_frame_from_context(const void* ucVoid) {
197 intptr_t* sp;
198 intptr_t* fp;
199 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
200 return frame(sp, fp, epc.pc());
201 }
202
203 frame os::get_sender_for_C_frame(frame* fr) {
204 #ifdef __thumb__
205 // We can't reliably get anything from a thumb C frame.
206 return frame();
207 #else
208 address pc = fr->sender_pc();
209 if (! is_safe_for_fp(pc)) {
210 return frame(fr->sender_sp(), (intptr_t *)NULL, pc);
211 } else {
212 return frame(fr->sender_sp(), fr->link() + os::C_frame_offset, pc);
213 }
214 #endif
215 }
216
217 //
218 // This actually returns two frames up. It does not return os::current_frame(),
219 // which is the actual current frame. Nor does it return os::get_native_stack(),
220 // which is the caller. It returns whoever called os::get_native_stack(). Not
221 // very intuitive, but consistent with how this API is implemented on other
222 // platforms.
223 //
224 frame os::current_frame() {
225 #ifdef __thumb__
226 // We can't reliably get anything from a thumb C frame.
227 return frame();
228 #else
229 register intptr_t* fp __asm__ (SPELL_REG_FP);
230 // fp is for os::current_frame. We want the fp for our caller.
231 frame myframe((intptr_t*)os::current_stack_pointer(), fp + os::C_frame_offset,
232 CAST_FROM_FN_PTR(address, os::current_frame));
233 frame caller_frame = os::get_sender_for_C_frame(&myframe);
234
235 if (os::is_first_C_frame(&caller_frame)) {
236 // stack is not walkable
237 // Assert below was added because it does not seem like this can ever happen.
238 // How can this frame ever be the first C frame since it is called from C code?
239 // If it does ever happen, undo the assert and comment here on when/why it happens.
240 assert(false, "this should never happen");
241 return frame();
242 }
243
244 // return frame for our caller's caller
245 return os::get_sender_for_C_frame(&caller_frame);
246 #endif
247 }
248
249 extern "C" address check_vfp_fault_instr;
250 extern "C" address check_vfp3_32_fault_instr;
251 extern "C" address check_simd_fault_instr;
252 extern "C" address check_mp_ext_fault_instr;
253
254 address check_vfp_fault_instr = NULL;
255 address check_vfp3_32_fault_instr = NULL;
256 address check_simd_fault_instr = NULL;
257 address check_mp_ext_fault_instr = NULL;
258
259 // Utility functions
260
261 extern "C" int JVM_handle_linux_signal(int sig, siginfo_t* info,
262 void* ucVoid, int abort_if_unrecognized) {
263 ucontext_t* uc = (ucontext_t*) ucVoid;
264
265 Thread* t = Thread::current_or_null_safe();
266
267 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
268 // (no destructors can be run)
269 os::ThreadCrashProtection::check_crash_protection(sig, t);
270
271 SignalHandlerMark shm(t);
272
273 if (sig == SIGILL &&
274 ((info->si_addr == (caddr_t)check_simd_fault_instr)
275 || info->si_addr == (caddr_t)check_vfp_fault_instr
276 || info->si_addr == (caddr_t)check_vfp3_32_fault_instr
277 || info->si_addr == (caddr_t)check_mp_ext_fault_instr)) {
278 // skip faulty instruction + instruction that sets return value to
279 // success and set return value to failure.
280 os::Linux::ucontext_set_pc(uc, (address)info->si_addr + 8);
281 uc->uc_mcontext.arm_r0 = 0;
282 return true;
283 }
284
285 // Note: it's not uncommon that JNI code uses signal/sigset to install
286 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
287 // or have a SIGILL handler when detecting CPU type). When that happens,
288 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
289 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
290 // that do not require siginfo/ucontext first.
291
292 if (sig == SIGPIPE || sig == SIGXFSZ) {
293 // allow chained handler to go first
294 if (os::Linux::chained_handler(sig, info, ucVoid)) {
295 return true;
296 } else {
297 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
298 return true;
299 }
300 }
301
302 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
303 if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
304 handle_assert_poison_fault(ucVoid, info->si_addr);
305 return 1;
306 }
307 #endif
308
309 JavaThread* thread = NULL;
310 VMThread* vmthread = NULL;
311 if (os::Linux::signal_handlers_are_installed) {
312 if (t != NULL ){
313 if(t->is_Java_thread()) {
314 thread = (JavaThread*)t;
315 }
316 else if(t->is_VM_thread()){
317 vmthread = (VMThread *)t;
318 }
319 }
320 }
321
322 address stub = NULL;
323 address pc = NULL;
324 bool unsafe_access = false;
325
326 if (info != NULL && uc != NULL && thread != NULL) {
327 pc = (address) os::Linux::ucontext_get_pc(uc);
328
329 // Handle ALL stack overflow variations here
330 if (sig == SIGSEGV) {
331 address addr = (address) info->si_addr;
332
333 if (StubRoutines::is_safefetch_fault(pc)) {
334 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
335 return 1;
336 }
337 // check if fault address is within thread stack
338 if (addr < thread->stack_base() &&
339 addr >= thread->stack_base() - thread->stack_size()) {
340 // stack overflow
341 if (thread->in_stack_yellow_reserved_zone(addr)) {
342 thread->disable_stack_yellow_reserved_zone();
343 if (thread->thread_state() == _thread_in_Java) {
344 // Throw a stack overflow exception. Guard pages will be reenabled
345 // while unwinding the stack.
346 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
347 } else {
348 // Thread was in the vm or native code. Return and try to finish.
349 return 1;
350 }
351 } else if (thread->in_stack_red_zone(addr)) {
352 // Fatal red zone violation. Disable the guard pages and fall through
353 // to handle_unexpected_exception way down below.
354 thread->disable_stack_red_zone();
355 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
356 } else {
357 // Accessing stack address below sp may cause SEGV if current
358 // thread has MAP_GROWSDOWN stack. This should only happen when
359 // current thread was created by user code with MAP_GROWSDOWN flag
360 // and then attached to VM. See notes in os_linux.cpp.
361 if (thread->osthread()->expanding_stack() == 0) {
362 thread->osthread()->set_expanding_stack();
363 if (os::Linux::manually_expand_stack(thread, addr)) {
364 thread->osthread()->clear_expanding_stack();
365 return 1;
366 }
367 thread->osthread()->clear_expanding_stack();
368 } else {
369 fatal("recursive segv. expanding stack.");
370 }
371 }
372 }
373 }
374
375 if (thread->thread_state() == _thread_in_Java) {
376 // Java thread running in Java code => find exception handler if any
377 // a fault inside compiled code, the interpreter, or a stub
378
379 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
380 stub = SharedRuntime::get_poll_stub(pc);
381 } else if (sig == SIGBUS) {
382 // BugId 4454115: A read from a MappedByteBuffer can fault
383 // here if the underlying file has been truncated.
384 // Do not crash the VM in such a case.
385 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
386 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
387 if (nm != NULL && nm->has_unsafe_access()) {
388 unsafe_access = true;
389 }
390 } else if (sig == SIGSEGV &&
391 MacroAssembler::uses_implicit_null_check(info->si_addr)) {
392 // Determination of interpreter/vtable stub/compiled code null exception
393 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
394 if (cb != NULL) {
395 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
396 }
397 } else if (sig == SIGILL && *(int *)pc == NativeInstruction::zombie_illegal_instruction) {
398 // Zombie
399 stub = SharedRuntime::get_handle_wrong_method_stub();
400 }
401 } else if (thread->thread_state() == _thread_in_vm &&
402 sig == SIGBUS && thread->doing_unsafe_access()) {
403 unsafe_access = true;
404 }
405
406 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
407 // and the heap gets shrunk before the field access.
408 if (sig == SIGSEGV || sig == SIGBUS) {
409 address addr = JNI_FastGetField::find_slowcase_pc(pc);
410 if (addr != (address)-1) {
411 stub = addr;
412 }
413 }
414 }
415
416 if (unsafe_access && stub == NULL) {
417 // it can be an unsafe access and we haven't found
418 // any other suitable exception reason,
419 // so assume it is an unsafe access.
420 address next_pc = pc + Assembler::InstructionSize;
421 #ifdef __thumb__
422 if (uc->uc_mcontext.arm_cpsr & PSR_T_BIT) {
423 next_pc = (address)((intptr_t)next_pc | 0x1);
424 }
425 #endif
426
427 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
428 }
429
430 if (stub != NULL) {
431 #ifdef __thumb__
432 if (uc->uc_mcontext.arm_cpsr & PSR_T_BIT) {
433 intptr_t p = (intptr_t)pc | 0x1;
434 pc = (address)p;
435
436 // Clear Thumb mode bit if we're redirected into the ARM ISA based code
437 if (((intptr_t)stub & 0x1) == 0) {
438 uc->uc_mcontext.arm_cpsr &= ~PSR_T_BIT;
439 }
440 } else {
441 // No Thumb2 compiled stubs are triggered from ARM ISA compiled JIT'd code today.
442 // The support needs to be added if that changes
443 assert((((intptr_t)stub & 0x1) == 0), "can't return to Thumb code");
444 }
445 #endif
446
447 // save all thread context in case we need to restore it
448 if (thread != NULL) thread->set_saved_exception_pc(pc);
449
450 os::Linux::ucontext_set_pc(uc, stub);
451 return true;
452 }
453
454 // signal-chaining
455 if (os::Linux::chained_handler(sig, info, ucVoid)) {
456 return true;
457 }
458
459 if (!abort_if_unrecognized) {
460 // caller wants another chance, so give it to him
461 return false;
462 }
463
464 if (pc == NULL && uc != NULL) {
465 pc = os::Linux::ucontext_get_pc(uc);
466 }
467
468 // unmask current signal
469 sigset_t newset;
470 sigemptyset(&newset);
471 sigaddset(&newset, sig);
472 sigprocmask(SIG_UNBLOCK, &newset, NULL);
473
474 VMError::report_and_die(t, sig, pc, info, ucVoid);
475
476 ShouldNotReachHere();
477 return false;
478 }
479
480 void os::Linux::init_thread_fpu_state(void) {
481 os::setup_fpu();
482 }
483
484 int os::Linux::get_fpu_control_word(void) {
485 return 0;
486 }
487
488 void os::Linux::set_fpu_control_word(int fpu_control) {
489 // Nothing to do
490 }
491
492 void os::setup_fpu() {
493 #if !defined(__SOFTFP__) && defined(__VFP_FP__)
494 // Turn on IEEE-754 compliant VFP mode
495 __asm__ volatile (
496 "mov %%r0, #0;"
497 "fmxr fpscr, %%r0"
498 : /* no output */ : /* no input */ : "r0"
499 );
500 #endif
501 }
502
503 bool os::is_allocatable(size_t bytes) {
504 return true;
505 }
506
507 ////////////////////////////////////////////////////////////////////////////////
508 // thread stack
509
510 // Minimum usable stack sizes required to get to user code. Space for
511 // HotSpot guard pages is added later.
512 size_t os::Posix::_compiler_thread_min_stack_allowed = (32 DEBUG_ONLY(+ 4)) * K;
513 size_t os::Posix::_java_thread_min_stack_allowed = (32 DEBUG_ONLY(+ 4)) * K;
514 size_t os::Posix::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K;
515
516 // return default stack size for thr_type
517 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
518 // default stack size (compiler thread needs larger stack)
519 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
520 return s;
521 }
522
523 /////////////////////////////////////////////////////////////////////////////
524 // helper functions for fatal error handler
525
526 void os::print_context(outputStream *st, const void *context) {
527 if (context == NULL) return;
528 const ucontext_t *uc = (const ucontext_t*)context;
529
530 st->print_cr("Registers:");
531 intx* reg_area = (intx*)&uc->uc_mcontext.arm_r0;
532 for (int r = 0; r < ARM_REGS_IN_CONTEXT; r++) {
533 st->print_cr(" %-3s = " INTPTR_FORMAT, as_Register(r)->name(), reg_area[r]);
534 }
535 #define U64_FORMAT "0x%016llx"
536 // now print flag register
537 st->print_cr(" %-4s = 0x%08lx", "cpsr",uc->uc_mcontext.arm_cpsr);
538 st->cr();
539
540 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
541 st->print_cr("Top of Stack: (sp=" INTPTR_FORMAT ")", p2i(sp));
542 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
543 st->cr();
544
545 // Note: it may be unsafe to inspect memory near pc. For example, pc may
546 // point to garbage if entry point in an nmethod is corrupted. Leave
547 // this at the end, and hope for the best.
548 address pc = os::Linux::ucontext_get_pc(uc);
549 print_instructions(st, pc, Assembler::InstructionSize);
550 st->cr();
551 }
552
553 void os::print_register_info(outputStream *st, const void *context) {
554 if (context == NULL) return;
555
556 const ucontext_t *uc = (const ucontext_t*)context;
557 intx* reg_area = (intx*)&uc->uc_mcontext.arm_r0;
558
559 st->print_cr("Register to memory mapping:");
560 st->cr();
561 for (int r = 0; r < ARM_REGS_IN_CONTEXT; r++) {
562 st->print_cr(" %-3s = " INTPTR_FORMAT, as_Register(r)->name(), reg_area[r]);
563 print_location(st, reg_area[r]);
564 st->cr();
565 }
566 st->cr();
567 }
568
569
570
571 typedef int64_t cmpxchg_long_func_t(int64_t, int64_t, volatile int64_t*);
572
573 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
574
575 int64_t os::atomic_cmpxchg_long_bootstrap(int64_t compare_value, int64_t exchange_value, volatile int64_t* dest) {
576 // try to use the stub:
577 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
578
579 if (func != NULL) {
580 os::atomic_cmpxchg_long_func = func;
581 return (*func)(compare_value, exchange_value, dest);
582 }
583 assert(Threads::number_of_threads() == 0, "for bootstrap only");
584
585 int64_t old_value = *dest;
586 if (old_value == compare_value)
587 *dest = exchange_value;
588 return old_value;
589 }
590 typedef int64_t load_long_func_t(const volatile int64_t*);
591
592 load_long_func_t* os::atomic_load_long_func = os::atomic_load_long_bootstrap;
593
594 int64_t os::atomic_load_long_bootstrap(const volatile int64_t* src) {
595 // try to use the stub:
596 load_long_func_t* func = CAST_TO_FN_PTR(load_long_func_t*, StubRoutines::atomic_load_long_entry());
597
598 if (func != NULL) {
599 os::atomic_load_long_func = func;
600 return (*func)(src);
601 }
602 assert(Threads::number_of_threads() == 0, "for bootstrap only");
603
604 int64_t old_value = *src;
605 return old_value;
606 }
607
608 typedef void store_long_func_t(int64_t, volatile int64_t*);
609
610 store_long_func_t* os::atomic_store_long_func = os::atomic_store_long_bootstrap;
611
612 void os::atomic_store_long_bootstrap(int64_t val, volatile int64_t* dest) {
613 // try to use the stub:
614 store_long_func_t* func = CAST_TO_FN_PTR(store_long_func_t*, StubRoutines::atomic_store_long_entry());
615
616 if (func != NULL) {
617 os::atomic_store_long_func = func;
618 return (*func)(val, dest);
619 }
620 assert(Threads::number_of_threads() == 0, "for bootstrap only");
621
622 *dest = val;
623 }
624
625 typedef int32_t atomic_add_func_t(int32_t add_value, volatile int32_t *dest);
626
627 atomic_add_func_t * os::atomic_add_func = os::atomic_add_bootstrap;
628
629 int32_t os::atomic_add_bootstrap(int32_t add_value, volatile int32_t *dest) {
630 atomic_add_func_t * func = CAST_TO_FN_PTR(atomic_add_func_t*,
631 StubRoutines::atomic_add_entry());
632 if (func != NULL) {
633 os::atomic_add_func = func;
634 return (*func)(add_value, dest);
635 }
636
637 int32_t old_value = *dest;
638 *dest = old_value + add_value;
639 return (old_value + add_value);
640 }
641
642 typedef int32_t atomic_xchg_func_t(int32_t exchange_value, volatile int32_t *dest);
643
644 atomic_xchg_func_t * os::atomic_xchg_func = os::atomic_xchg_bootstrap;
645
646 int32_t os::atomic_xchg_bootstrap(int32_t exchange_value, volatile int32_t *dest) {
647 atomic_xchg_func_t * func = CAST_TO_FN_PTR(atomic_xchg_func_t*,
648 StubRoutines::atomic_xchg_entry());
649 if (func != NULL) {
650 os::atomic_xchg_func = func;
651 return (*func)(exchange_value, dest);
652 }
653
654 int32_t old_value = *dest;
655 *dest = exchange_value;
656 return (old_value);
657 }
658
659 typedef int32_t cmpxchg_func_t(int32_t, int32_t, volatile int32_t*);
660
661 cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap;
662
663 int32_t os::atomic_cmpxchg_bootstrap(int32_t compare_value, int32_t exchange_value, volatile int32_t* dest) {
664 // try to use the stub:
665 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
666
667 if (func != NULL) {
668 os::atomic_cmpxchg_func = func;
669 return (*func)(compare_value, exchange_value, dest);
670 }
671 assert(Threads::number_of_threads() == 0, "for bootstrap only");
672
673 int32_t old_value = *dest;
674 if (old_value == compare_value)
675 *dest = exchange_value;
676 return old_value;
677 }
678
679
680 #ifndef PRODUCT
681 void os::verify_stack_alignment() {
682 }
683 #endif
684
685 int os::extra_bang_size_in_bytes() {
686 // ARM does not require an additional stack bang.
687 return 0;
688 }