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src/os_cpu/linux_mips/vm/os_linux_mips.cpp@52ea28d233d2
src/os_cpu/linux_mips/vm/os_linux_mips.cpp
Thu, 07 Sep 2017 09:12:16 +0800
- author
- aoqi
- date
- Thu, 07 Sep 2017 09:12:16 +0800
- changeset 6880
- 52ea28d233d2
- parent 414
- c5f826fdfc22
- child 8012
- 5efbe2fd5486
- permissions
- -rw-r--r--
#5745 [Code Reorganization] code cleanup and code style fix
This is a huge patch, but only code cleanup, code style fix and useless code deletion are included, for example:
tab -> two spaces, deleted spacees at the end of a line, delete useless comments.
This patch also included:
Declaration and definition of class MacroAssembler is moved from assembler_mips.h/cpp to macroAssembler_mips.h/cpp
1 /*
2 * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2015, 2016, Loongson Technology. All rights reserved.
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 */
26 // no precompiled headers
27 #include "asm/macroAssembler.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 "os_share_linux.hpp"
38 #include "prims/jniFastGetField.hpp"
39 #include "prims/jvm.h"
40 #include "prims/jvm_misc.hpp"
41 #include "runtime/arguments.hpp"
42 #include "runtime/extendedPC.hpp"
43 #include "runtime/frame.inline.hpp"
44 #include "runtime/interfaceSupport.hpp"
45 #include "runtime/java.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "runtime/osThread.hpp"
49 #include "runtime/sharedRuntime.hpp"
50 #include "runtime/stubRoutines.hpp"
51 #include "runtime/thread.inline.hpp"
52 #include "runtime/timer.hpp"
53 #include "utilities/events.hpp"
54 #include "utilities/vmError.hpp"
55 #include "utilities/debug.hpp"
56 #include "compiler/disassembler.hpp"
57 // put OS-includes here
58 # include <sys/types.h>
59 # include <sys/mman.h>
60 # include <pthread.h>
61 # include <signal.h>
62 # include <errno.h>
63 # include <dlfcn.h>
64 # include <stdlib.h>
65 # include <stdio.h>
66 # include <unistd.h>
67 # include <sys/resource.h>
68 # include <pthread.h>
69 # include <sys/stat.h>
70 # include <sys/time.h>
71 # include <sys/utsname.h>
72 # include <sys/socket.h>
73 # include <sys/wait.h>
74 # include <pwd.h>
75 # include <poll.h>
76 # include <ucontext.h>
77 # include <fpu_control.h>
79 #define REG_SP 29
80 #define REG_FP 30
82 address os::current_stack_pointer() {
83 register void *sp __asm__ ("$29");
84 return (address) sp;
85 }
87 char* os::non_memory_address_word() {
88 // Must never look like an address returned by reserve_memory,
89 // even in its subfields (as defined by the CPU immediate fields,
90 // if the CPU splits constants across multiple instructions).
92 return (char*) -1;
93 }
95 void os::initialize_thread(Thread* thr) {
96 // Nothing to do.
97 }
99 address os::Linux::ucontext_get_pc(ucontext_t * uc) {
100 //return (address)uc->uc_mcontext.gregs[REG_PC];
101 return (address)uc->uc_mcontext.pc;//aoqi:what is gregs?
102 }
104 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
105 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
106 }
108 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
109 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
110 }
112 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
113 // is currently interrupted by SIGPROF.
114 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
115 // frames. Currently we don't do that on Linux, so it's the same as
116 // os::fetch_frame_from_context().
117 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
118 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
120 assert(thread != NULL, "just checking");
121 assert(ret_sp != NULL, "just checking");
122 assert(ret_fp != NULL, "just checking");
124 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
125 }
127 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
128 intptr_t** ret_sp, intptr_t** ret_fp) {
130 ExtendedPC epc;
131 ucontext_t* uc = (ucontext_t*)ucVoid;
133 address pc = (address)os::Linux::ucontext_get_pc(uc);
135 /* Jin: to capture invalid 32-bit PC, for debbuging */
136 if (((long)pc & 0xFFFFFFFF00000000UL) == 0)
137 {
138 pc = (address)((long)pc | 0x5500000000UL);
139 tty->print_cr("<Error> 32-bit pc: %lx", pc);
140 }
142 if (uc != NULL) {
143 epc = ExtendedPC(pc);
144 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
145 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
146 } else {
147 // construct empty ExtendedPC for return value checking
148 epc = ExtendedPC(NULL);
149 if (ret_sp) *ret_sp = (intptr_t *)NULL;
150 if (ret_fp) *ret_fp = (intptr_t *)NULL;
151 }
153 return epc;
154 }
156 frame os::fetch_frame_from_context(void* ucVoid) {
157 intptr_t* sp;
158 intptr_t* fp;
159 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
160 return frame(sp, fp, epc.pc());
161 }
163 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
164 // turned off by -fomit-frame-pointer,
165 frame os::get_sender_for_C_frame(frame* fr) {
166 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
167 }
169 //intptr_t* _get_previous_fp() {
170 jint* os::get_previous_fp() {
171 int *pc;
172 int sp;
173 int *pc_limit = (int*)(void*)&os::get_previous_fp;
174 int insn;
176 {
177 l_pc:;
178 pc = (int*)&&l_pc;
179 __asm__ __volatile__ ("move %0, $sp" : "=r" (sp));
180 }
182 do {
183 --pc;
184 insn = *pc;
185 switch(bitfield(insn, 16, 16)) {
186 case 0x27bd: /* addiu $sp,$sp,-i */
187 case 0x23bd: /* addi $sp,$sp,-i */
188 case 0x67bd: /* daddiu $sp,$sp,-i */
189 case 0x63bd: /* daddi $sp,$sp,-i */
190 assert ((short)bitfield(insn, 0, 16)<0, "bad frame");
191 sp -= (short)bitfield(insn, 0, 16);
192 return (jint*)sp;
193 }
194 } while (pc>pc_limit);
196 ShouldNotReachHere();
197 }
200 frame os::current_frame() {
201 intptr_t* fp = (intptr_t*)get_previous_fp();
202 frame myframe((intptr_t*)os::current_stack_pointer(),
203 (intptr_t*)fp,
204 CAST_FROM_FN_PTR(address, os::current_frame));
205 if (os::is_first_C_frame(&myframe)) {
206 // stack is not walkable
207 return frame();
208 } else {
209 return os::get_sender_for_C_frame(&myframe);
210 }
211 }
213 //x86 add 2 new assemble function here!
214 extern "C" int
215 JVM_handle_linux_signal(int sig,
216 siginfo_t* info,
217 void* ucVoid,
218 int abort_if_unrecognized) {
219 #ifdef PRINT_SIGNAL_HANDLE
220 tty->print_cr("Signal: signo=%d, sicode=%d, sierrno=%d, siaddr=%lx",
221 info->si_signo,
222 info->si_code,
223 info->si_errno,
224 info->si_addr);
225 #endif
227 ucontext_t* uc = (ucontext_t*) ucVoid;
229 Thread* t = ThreadLocalStorage::get_thread_slow();
231 SignalHandlerMark shm(t);
233 // Note: it's not uncommon that JNI code uses signal/sigset to install
234 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
235 // or have a SIGILL handler when detecting CPU type). When that happens,
236 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
237 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
238 // that do not require siginfo/ucontext first.
240 //if (sig == SIGPIPE || sig == SIGXFSZ) {
241 if (sig == SIGPIPE) {
242 // allow chained handler to go first
243 if (os::Linux::chained_handler(sig, info, ucVoid)) {
244 return true;
245 } else {
246 if (PrintMiscellaneous && (WizardMode || Verbose)) {
247 warning("Ignoring SIGPIPE - see bug 4229104");
248 }
249 return true;
250 }
251 }
253 JavaThread* thread = NULL;
254 VMThread* vmthread = NULL;
255 if (os::Linux::signal_handlers_are_installed) {
256 if (t != NULL ){
257 if(t->is_Java_thread()) {
258 #ifdef PRINT_SIGNAL_HANDLE
259 //tty->print_cr("this thread is a java thread");
260 #endif
261 thread = (JavaThread*)t;
262 }
263 else if(t->is_VM_thread()){
264 #ifdef PRINT_SIGNAL_HANDLE
265 //tty->print_cr("this thread is a VM thread\n");
266 #endif
267 vmthread = (VMThread *)t;
268 }
269 }
270 }
272 // decide if this trap can be handled by a stub
273 address stub = NULL;
274 address pc = NULL;
276 pc = (address) os::Linux::ucontext_get_pc(uc);
277 #ifdef PRINT_SIGNAL_HANDLE
278 tty->print_cr("pc=%lx", pc);
279 os::print_context(tty, uc);
280 #endif
281 //%note os_trap_1
282 if (info != NULL && uc != NULL && thread != NULL) {
283 pc = (address) os::Linux::ucontext_get_pc(uc);
284 // Handle ALL stack overflow variations here
285 if (sig == SIGSEGV) {
286 address addr = (address) info->si_addr;
287 #ifdef PRINT_SIGNAL_HANDLE
288 //tty->print("handle all stack overflow variations: ");
289 /*tty->print("addr = %lx, stack base = %lx, stack top = %lx\n",
290 addr,
291 thread->stack_base(),
292 thread->stack_base() - thread->stack_size());
293 */
294 #endif
296 // check if fault address is within thread stack
297 if (addr < thread->stack_base() &&
298 addr >= thread->stack_base() - thread->stack_size()) {
299 // stack overflow
300 #ifdef PRINT_SIGNAL_HANDLE
301 tty->print("stack exception check \n");
302 #endif
303 if (thread->in_stack_yellow_zone(addr)) {
304 #ifdef PRINT_SIGNAL_HANDLE
305 tty->print("exception addr is in yellow zone\n");
306 #endif
307 thread->disable_stack_yellow_zone();
308 if (thread->thread_state() == _thread_in_Java) {
309 // Throw a stack overflow exception. Guard pages will be reenabled
310 // while unwinding the stack.
311 #ifdef PRINT_SIGNAL_HANDLE
312 tty->print("this thread is in java\n");
313 #endif
314 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
315 } else {
316 // Thread was in the vm or native code. Return and try to finish.
317 #ifdef PRINT_SIGNAL_HANDLE
318 tty->print("this thread is in vm or native codes and return\n");
319 #endif
320 return 1;
321 }
322 } else if (thread->in_stack_red_zone(addr)) {
323 // Fatal red zone violation. Disable the guard pages and fall through
324 // to handle_unexpected_exception way down below.
325 #ifdef PRINT_SIGNAL_HANDLE
326 tty->print("exception addr is in red zone\n");
327 #endif
328 thread->disable_stack_red_zone();
329 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
331 // This is a likely cause, but hard to verify. Let's just print
332 // it as a hint.
333 tty->print_raw_cr("Please check if any of your loaded .so files has "
334 "enabled executable stack (see man page execstack(8))");
335 } else {
336 // Accessing stack address below sp may cause SEGV if current
337 // thread has MAP_GROWSDOWN stack. This should only happen when
338 // current thread was created by user code with MAP_GROWSDOWN flag
339 // and then attached to VM. See notes in os_linux.cpp.
340 #ifdef PRINT_SIGNAL_HANDLE
341 tty->print("exception addr is neither in yellow zone nor in the red one\n");
342 #endif
343 if (thread->osthread()->expanding_stack() == 0) {
344 thread->osthread()->set_expanding_stack();
345 if (os::Linux::manually_expand_stack(thread, addr)) {
346 thread->osthread()->clear_expanding_stack();
347 return 1;
348 }
349 thread->osthread()->clear_expanding_stack();
350 } else {
351 fatal("recursive segv. expanding stack.");
352 }
353 }
354 } //addr <
355 } //sig == SIGSEGV
357 if (thread->thread_state() == _thread_in_Java) {
358 // Java thread running in Java code => find exception handler if any
359 // a fault inside compiled code, the interpreter, or a stub
360 #ifdef PRINT_SIGNAL_HANDLE
361 tty->print("java thread running in java code\n");
362 tty->print_cr("polling address = %lx, sig=%d", os::get_polling_page(), sig);
363 #endif
364 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
366 stub = SharedRuntime::get_poll_stub(pc);
367 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
368 // BugId 4454115: A read from a MappedByteBuffer can fault
369 // here if the underlying file has been truncated.
370 // Do not crash the VM in such a case.
371 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
372 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
373 #ifdef PRINT_SIGNAL_HANDLE
374 tty->print("cb = %lx, nm = %lx\n", cb, nm);
375 #endif
376 if (nm != NULL && nm->has_unsafe_access()) {
377 stub = StubRoutines::handler_for_unsafe_access();
378 }
379 } else if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
380 // HACK: si_code does not work on linux 2.2.12-20!!!
381 int op = pc[0] & 0x3f;
382 int op1 = pc[3] & 0x3f;
383 tty->print_cr("unknown opcode 0x%X -0x%X with SIGFPE.", op, op1);
384 //FIXME, Must port to mips code!!
385 switch (op) {
386 case 0x1e: //ddiv
387 case 0x1f: //ddivu
388 case 0x1a: //div
389 case 0x1b: //divu
390 case 0x34: //trap
391 /* In MIPS, div_by_zero exception can only be triggered by explicit 'trap'.
392 * Ref: [c1_LIRAssembler_mips.cpp] arithmetic_idiv()
393 */
394 stub = SharedRuntime::continuation_for_implicit_exception(thread,
395 pc,
396 SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
397 break;
398 default:
399 // TODO: handle more cases if we are using other x86 instructions
400 // that can generate SIGFPE signal on linux.
401 tty->print_cr("unknown opcode 0x%X -0x%X with SIGFPE.", op, op1);
402 //fatal("please update this code.");
403 }
404 }
405 else if (sig == SIGSEGV &&
406 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
407 // Determination of interpreter/vtable stub/compiled code null exception
408 #ifdef PRINT_SIGNAL_HANDLE
409 tty->print("continuation for implicit exception\n");
410 #endif
411 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
412 }
413 else if (thread->thread_state() == _thread_in_Java && sig == SIGILL) {
414 //Since kernel does not have emulation of PS instructions yet, the emulation must be handled here.
415 //The method is to trigger kernel emulation of float emulation.
416 int inst = *(int*)pc;
417 int ops = (inst >> 26) & 0x3f;
418 int ops_fmt = (inst >> 21) & 0x1f;
419 int op = inst & 0x3f;
420 if (ops == Assembler::cop1_op && ops_fmt == Assembler::ps_fmt) {
421 int ft, fs, fd;
422 ft = (inst >> 16) & 0x1f;
423 fs = (inst >> 11) & 0x1f;
424 fd = (inst >> 6) & 0x1f;
425 float ft_upper, ft_lower, fs_upper, fs_lower, fd_upper, fd_lower;
426 double ft_value, fs_value, fd_value;
427 ft_value = uc->uc_mcontext.fpregs.fp_r.fp_dregs[ft];
428 fs_value = uc->uc_mcontext.fpregs.fp_r.fp_dregs[fs];
429 __asm__ __volatile__ (
430 "cvt.s.pl %0, %4\n\t"
431 "cvt.s.pu %1, %4\n\t"
432 "cvt.s.pl %2, %5\n\t"
433 "cvt.s.pu %3, %5\n\t"
434 : "=f" (fs_lower), "=f" (fs_upper), "=f" (ft_lower), "=f" (ft_upper)
435 : "f" (fs_value), "f" (ft_value)
436 );
438 switch (op) {
439 case Assembler::fadd_op:
440 __asm__ __volatile__ (
441 "add.s %1, %3, %5\n\t"
442 "add.s %2, %4, %6\n\t"
443 "pll.ps %0, %1, %2\n\t"
444 : "=f" (fd_value), "=f" (fd_upper), "=f" (fd_lower)
445 : "f" (fs_upper), "f" (fs_lower), "f" (ft_upper), "f" (ft_lower)
446 );
447 uc->uc_mcontext.fpregs.fp_r.fp_dregs[fd] = fd_value;
448 stub = pc + 4;
449 break;
450 case Assembler::fsub_op:
451 //fd = fs - ft
452 __asm__ __volatile__ (
453 "sub.s %1, %3, %5\n\t"
454 "sub.s %2, %4, %6\n\t"
455 "pll.ps %0, %1, %2\n\t"
456 : "=f" (fd_value), "=f" (fd_upper), "=f" (fd_lower)
457 : "f" (fs_upper), "f" (fs_lower), "f" (ft_upper), "f" (ft_lower)
458 );
459 uc->uc_mcontext.fpregs.fp_r.fp_dregs[fd] = fd_value;
460 stub = pc + 4;
461 break;
462 case Assembler::fmul_op:
463 __asm__ __volatile__ (
464 "mul.s %1, %3, %5\n\t"
465 "mul.s %2, %4, %6\n\t"
466 "pll.ps %0, %1, %2\n\t"
467 : "=f" (fd_value), "=f" (fd_upper), "=f" (fd_lower)
468 : "f" (fs_upper), "f" (fs_lower), "f" (ft_upper), "f" (ft_lower)
469 );
470 uc->uc_mcontext.fpregs.fp_r.fp_dregs[fd] = fd_value;
471 stub = pc + 4;
472 break;
473 default:
474 tty->print_cr("unknown cop1 opcode 0x%x with SIGILL.", op);
475 }
476 }
477 else if (ops == Assembler::cop1x_op /*&& op == Assembler::nmadd_ps_op*/) {
478 // madd.ps is not used, the code below were not tested
479 int fr, ft, fs, fd;
480 float fr_upper, fr_lower, fs_upper, fs_lower, ft_upper, ft_lower, fd_upper, fd_lower;
481 double fr_value, ft_value, fs_value, fd_value;
482 switch (op) {
483 case Assembler::madd_ps_op:
484 // fd = (fs * ft) + fr
485 fr = (inst >> 21) & 0x1f;
486 ft = (inst >> 16) & 0x1f;
487 fs = (inst >> 11) & 0x1f;
488 fd = (inst >> 6) & 0x1f;
489 fr_value = uc->uc_mcontext.fpregs.fp_r.fp_dregs[fr];
490 ft_value = uc->uc_mcontext.fpregs.fp_r.fp_dregs[ft];
491 fs_value = uc->uc_mcontext.fpregs.fp_r.fp_dregs[fs];
492 __asm__ __volatile__ (
493 "cvt.s.pu %3, %9\n\t"
494 "cvt.s.pl %4, %9\n\t"
495 "cvt.s.pu %5, %10\n\t"
496 "cvt.s.pl %6, %10\n\t"
497 "cvt.s.pu %7, %11\n\t"
498 "cvt.s.pl %8, %11\n\t"
499 "madd.s %1, %3, %5, %7\n\t"
500 "madd.s %2, %4, %6, %8\n\t"
501 "pll.ps %0, %1, %2\n\t"
502 : "=f" (fd_value), "=f" (fd_upper), "=f" (fd_lower), "=f" (fr_upper), "=f" (fr_lower), "=f" (fs_upper), "=f" (fs_lower), "=f" (ft_upper), "=f" (ft_lower)
503 : "f" (fr_value)/*9*/, "f" (fs_value)/*10*/, "f" (ft_value)/*11*/
504 );
505 uc->uc_mcontext.fpregs.fp_r.fp_dregs[fd] = fd_value;
506 stub = pc + 4;
507 break;
508 default:
509 tty->print_cr("unknown cop1x opcode 0x%x with SIGILL.", op);
510 }
511 }
512 } //SIGILL
513 } else if (thread->thread_state() == _thread_in_vm &&
514 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
515 thread->doing_unsafe_access()) {
516 #ifdef PRINT_SIGNAL_HANDLE
517 tty->print_cr("SIGBUS in vm thread \n");
518 #endif
519 stub = StubRoutines::handler_for_unsafe_access();
520 }
522 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
523 // and the heap gets shrunk before the field access.
524 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
525 #ifdef PRINT_SIGNAL_HANDLE
526 //tty->print("jni fast get trap: ");
527 #endif
528 address addr = JNI_FastGetField::find_slowcase_pc(pc);
529 if (addr != (address)-1) {
530 stub = addr;
531 }
532 #ifdef PRINT_SIGNAL_HANDLE
533 //tty->print_cr("addr = %d, stub = %lx", addr, stub);
534 #endif
535 }
537 // Check to see if we caught the safepoint code in the
538 // process of write protecting the memory serialization page.
539 // It write enables the page immediately after protecting it
540 // so we can just return to retry the write.
541 if ((sig == SIGSEGV) &&
542 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
543 // Block current thread until the memory serialize page permission restored.
544 #ifdef PRINT_SIGNAL_HANDLE
545 //tty->print("write protecting the memory serialiazation page\n");
546 #endif
547 os::block_on_serialize_page_trap();
548 return true;
549 }
550 }
552 // Execution protection violation
553 //
554 // This should be kept as the last step in the triage. We don't
555 // have a dedicated trap number for a no-execute fault, so be
556 // conservative and allow other handlers the first shot.
557 //
558 // Note: We don't test that info->si_code == SEGV_ACCERR here.
559 // this si_code is so generic that it is almost meaningless; and
560 // the si_code for this condition may change in the future.
561 // Furthermore, a false-positive should be harmless.
562 if (UnguardOnExecutionViolation > 0 &&
563 //(sig == SIGSEGV || sig == SIGBUS) &&
564 //uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) {
565 (sig == SIGSEGV || sig == SIGBUS
566 #ifdef OPT_RANGECHECK
567 || sig == SIGSYS
568 #endif
569 ) &&
570 //(uc->uc_mcontext.cause == 2 || uc->uc_mcontext.cause == 3)) {
571 (uc->uc_mcontext.hi1 == 2 || uc->uc_mcontext.hi1 == 3)) {
572 //aoqi: copy from jdk1.5, dont understand the struct mcontext_t.
573 #ifdef PRINT_SIGNAL_HANDLE
574 tty->print_cr("execution protection violation\n");
575 #endif
577 int page_size = os::vm_page_size();
578 address addr = (address) info->si_addr;
579 address pc = os::Linux::ucontext_get_pc(uc);
580 // Make sure the pc and the faulting address are sane.
581 //
582 // If an instruction spans a page boundary, and the page containing
583 // the beginning of the instruction is executable but the following
584 // page is not, the pc and the faulting address might be slightly
585 // different - we still want to unguard the 2nd page in this case.
586 //
587 // 15 bytes seems to be a (very) safe value for max instruction size.
588 bool pc_is_near_addr =
589 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
590 bool instr_spans_page_boundary =
591 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
592 (intptr_t) page_size) > 0);
594 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
595 static volatile address last_addr =
596 (address) os::non_memory_address_word();
598 // In conservative mode, don't unguard unless the address is in the VM
599 if (addr != last_addr &&
600 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
602 // Set memory to RWX and retry
603 address page_start =
604 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
605 bool res = os::protect_memory((char*) page_start, page_size,
606 os::MEM_PROT_RWX);
608 if (PrintMiscellaneous && Verbose) {
609 char buf[256];
610 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
611 "at " INTPTR_FORMAT
612 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
613 page_start, (res ? "success" : "failed"), errno);
614 tty->print_raw_cr(buf);
615 }
616 stub = pc;
618 // Set last_addr so if we fault again at the same address, we don't end
619 // up in an endless loop.
620 //
621 // There are two potential complications here. Two threads trapping at
622 // the same address at the same time could cause one of the threads to
623 // think it already unguarded, and abort the VM. Likely very rare.
624 //
625 // The other race involves two threads alternately trapping at
626 // different addresses and failing to unguard the page, resulting in
627 // an endless loop. This condition is probably even more unlikely than
628 // the first.
629 //
630 // Although both cases could be avoided by using locks or thread local
631 // last_addr, these solutions are unnecessary complication: this
632 // handler is a best-effort safety net, not a complete solution. It is
633 // disabled by default and should only be used as a workaround in case
634 // we missed any no-execute-unsafe VM code.
636 last_addr = addr;
637 }
638 }
639 }
641 if (stub != NULL) {
642 #ifdef PRINT_SIGNAL_HANDLE
643 //tty->print_cr("resolved stub=%lx\n",stub);
644 #endif
645 // save all thread context in case we need to restore it
646 if (thread != NULL) thread->set_saved_exception_pc(pc);
648 uc->uc_mcontext.pc = (greg_t)stub;
649 return true;
650 }
652 // signal-chaining
653 if (os::Linux::chained_handler(sig, info, ucVoid)) {
654 #ifdef PRINT_SIGNAL_HANDLE
655 tty->print_cr("signal chaining\n");
656 #endif
657 return true;
658 }
660 if (!abort_if_unrecognized) {
661 // caller wants another chance, so give it to him
662 #ifdef PRINT_SIGNAL_HANDLE
663 tty->print_cr("abort becauce of unrecognized\n");
664 #endif
665 return false;
666 }
668 if (pc == NULL && uc != NULL) {
669 pc = os::Linux::ucontext_get_pc(uc);
670 }
672 // unmask current signal
673 sigset_t newset;
674 sigemptyset(&newset);
675 sigaddset(&newset, sig);
676 sigprocmask(SIG_UNBLOCK, &newset, NULL);
677 #ifdef PRINT_SIGNAL_HANDLE
678 tty->print_cr("VMError in signal handler\n");
679 #endif
680 VMError err(t, sig, pc, info, ucVoid);
681 err.report_and_die();
683 ShouldNotReachHere();
684 }
686 // FCSR:...|24| 23 |22|21|...
687 // ...|FS|FCC0|FO|FN|...
688 void os::Linux::init_thread_fpu_state(void) {
689 if (SetFSFOFN == 999)
690 return;
691 int fs = (SetFSFOFN / 100)? 1:0;
692 int fo = ((SetFSFOFN % 100) / 10)? 1:0;
693 int fn = (SetFSFOFN % 10)? 1:0;
694 int mask = fs << 24 | fo << 22 | fn << 21;
696 int fcsr = get_fpu_control_word();
697 fcsr = fcsr | mask;
698 set_fpu_control_word(fcsr);
699 /*
700 if (fcsr != get_fpu_control_word())
701 tty->print_cr(" fail to set to %lx, get_fpu_control_word:%lx", fcsr, get_fpu_control_word());
702 */
703 }
705 int os::Linux::get_fpu_control_word(void) {
706 int fcsr;
707 __asm__ __volatile__ (
708 ".set noat;"
709 "daddiu %0, $0, 0;"
710 "cfc1 %0, $31;"
711 : "=r" (fcsr)
712 );
713 return fcsr;
714 }
716 void os::Linux::set_fpu_control_word(int fpu_control) {
717 __asm__ __volatile__ (
718 ".set noat;"
719 "ctc1 %0, $31;"
720 :
721 : "r" (fpu_control)
722 );
723 }
725 bool os::is_allocatable(size_t bytes) {
727 if (bytes < 2 * G) {
728 return true;
729 }
731 char* addr = reserve_memory(bytes, NULL);
733 if (addr != NULL) {
734 release_memory(addr, bytes);
735 }
737 return addr != NULL;
738 }
740 ////////////////////////////////////////////////////////////////////////////////
741 // thread stack
743 size_t os::Linux::min_stack_allowed = 96 * K;
746 // Test if pthread library can support variable thread stack size. LinuxThreads
747 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads
748 // in floating stack mode and NPTL support variable stack size.
749 bool os::Linux::supports_variable_stack_size() {
750 if (os::Linux::is_NPTL()) {
751 // NPTL, yes
752 return true;
754 } else {
755 // Note: We can't control default stack size when creating a thread.
756 // If we use non-default stack size (pthread_attr_setstacksize), both
757 // floating stack and non-floating stack LinuxThreads will return the
758 // same value. This makes it impossible to implement this function by
759 // detecting thread stack size directly.
760 //
761 // An alternative approach is to check %gs. Fixed-stack LinuxThreads
762 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use
763 // %gs (either as LDT selector or GDT selector, depending on kernel)
764 // to access thread specific data.
765 //
766 // Note that %gs is a reserved glibc register since early 2001, so
767 // applications are not allowed to change its value (Ulrich Drepper from
768 // Redhat confirmed that all known offenders have been modified to use
769 // either %fs or TSD). In the worst case scenario, when VM is embedded in
770 // a native application that plays with %gs, we might see non-zero %gs
771 // even LinuxThreads is running in fixed stack mode. As the result, we'll
772 // return true and skip _thread_safety_check(), so we may not be able to
773 // detect stack-heap collisions. But otherwise it's harmless.
774 //
775 return false;
776 }
777 }
779 // return default stack size for thr_type
780 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
781 // default stack size (compiler thread needs larger stack)
782 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
783 return s;
784 }
786 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
787 // Creating guard page is very expensive. Java thread has HotSpot
788 // guard page, only enable glibc guard page for non-Java threads.
789 return (thr_type == java_thread ? 0 : page_size());
790 }
792 // Java thread:
793 //
794 // Low memory addresses
795 // +------------------------+
796 // | |\ JavaThread created by VM does not have glibc
797 // | glibc guard page | - guard, attached Java thread usually has
798 // | |/ 1 page glibc guard.
799 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
800 // | |\
801 // | HotSpot Guard Pages | - red and yellow pages
802 // | |/
803 // +------------------------+ JavaThread::stack_yellow_zone_base()
804 // | |\
805 // | Normal Stack | -
806 // | |/
807 // P2 +------------------------+ Thread::stack_base()
808 //
809 // Non-Java thread:
810 //
811 // Low memory addresses
812 // +------------------------+
813 // | |\
814 // | glibc guard page | - usually 1 page
815 // | |/
816 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
817 // | |\
818 // | Normal Stack | -
819 // | |/
820 // P2 +------------------------+ Thread::stack_base()
821 //
822 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
823 // pthread_attr_getstack()
825 static void current_stack_region(address * bottom, size_t * size) {
826 if (os::Linux::is_initial_thread()) {
827 // initial thread needs special handling because pthread_getattr_np()
828 // may return bogus value.
829 *bottom = os::Linux::initial_thread_stack_bottom();
830 *size = os::Linux::initial_thread_stack_size();
831 } else {
832 pthread_attr_t attr;
834 int rslt = pthread_getattr_np(pthread_self(), &attr);
836 // JVM needs to know exact stack location, abort if it fails
837 if (rslt != 0) {
838 if (rslt == ENOMEM) {
839 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
840 } else {
841 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt));
842 }
843 }
845 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
846 fatal("Can not locate current stack attributes!");
847 }
849 pthread_attr_destroy(&attr);
851 }
852 assert(os::current_stack_pointer() >= *bottom &&
853 os::current_stack_pointer() < *bottom + *size, "just checking");
854 }
856 address os::current_stack_base() {
857 address bottom;
858 size_t size;
859 current_stack_region(&bottom, &size);
860 return (bottom + size);
861 }
863 size_t os::current_stack_size() {
864 // stack size includes normal stack and HotSpot guard pages
865 address bottom;
866 size_t size;
867 current_stack_region(&bottom, &size);
868 return size;
869 }
871 /////////////////////////////////////////////////////////////////////////////
872 // helper functions for fatal error handler
873 void os::print_register_info(outputStream *st, void *context) {
874 if (context == NULL) return;
876 ucontext_t *uc = (ucontext_t*)context;
878 st->print_cr("Register to memory mapping:");
879 st->cr();
880 // this is horrendously verbose but the layout of the registers in the
881 // // context does not match how we defined our abstract Register set, so
882 // // we can't just iterate through the gregs area
883 //
884 // // this is only for the "general purpose" registers
885 st->print("R0=" ); print_location(st, uc->uc_mcontext.gregs[0]);
886 st->print("AT=" ); print_location(st, uc->uc_mcontext.gregs[1]);
887 st->print("V0=" ); print_location(st, uc->uc_mcontext.gregs[2]);
888 st->print("V1=" ); print_location(st, uc->uc_mcontext.gregs[3]);
889 st->cr();
890 st->print("A0=" ); print_location(st, uc->uc_mcontext.gregs[4]);
891 st->print("A1=" ); print_location(st, uc->uc_mcontext.gregs[5]);
892 st->print("A2=" ); print_location(st, uc->uc_mcontext.gregs[6]);
893 st->print("A3=" ); print_location(st, uc->uc_mcontext.gregs[7]);
894 st->cr();
895 st->print("A4=" ); print_location(st, uc->uc_mcontext.gregs[8]);
896 st->print("A5=" ); print_location(st, uc->uc_mcontext.gregs[9]);
897 st->print("A6=" ); print_location(st, uc->uc_mcontext.gregs[10]);
898 st->print("A7=" ); print_location(st, uc->uc_mcontext.gregs[11]);
899 st->cr();
900 st->print("T0=" ); print_location(st, uc->uc_mcontext.gregs[12]);
901 st->print("T1=" ); print_location(st, uc->uc_mcontext.gregs[13]);
902 st->print("T2=" ); print_location(st, uc->uc_mcontext.gregs[14]);
903 st->print("T3=" ); print_location(st, uc->uc_mcontext.gregs[15]);
904 st->cr();
905 st->print("S0=" ); print_location(st, uc->uc_mcontext.gregs[16]);
906 st->print("S1=" ); print_location(st, uc->uc_mcontext.gregs[17]);
907 st->print("S2=" ); print_location(st, uc->uc_mcontext.gregs[18]);
908 st->print("S3=" ); print_location(st, uc->uc_mcontext.gregs[19]);
909 st->cr();
910 st->print("S4=" ); print_location(st, uc->uc_mcontext.gregs[20]);
911 st->print("S5=" ); print_location(st, uc->uc_mcontext.gregs[21]);
912 st->print("S6=" ); print_location(st, uc->uc_mcontext.gregs[22]);
913 st->print("S7=" ); print_location(st, uc->uc_mcontext.gregs[23]);
914 st->cr();
915 st->print("T8=" ); print_location(st, uc->uc_mcontext.gregs[24]);
916 st->print("T9=" ); print_location(st, uc->uc_mcontext.gregs[25]);
917 st->print("K0=" ); print_location(st, uc->uc_mcontext.gregs[26]);
918 st->print("K1=" ); print_location(st, uc->uc_mcontext.gregs[27]);
919 st->cr();
920 st->print("GP=" ); print_location(st, uc->uc_mcontext.gregs[28]);
921 st->print("SP=" ); print_location(st, uc->uc_mcontext.gregs[29]);
922 st->print("FP=" ); print_location(st, uc->uc_mcontext.gregs[30]);
923 st->print("RA=" ); print_location(st, uc->uc_mcontext.gregs[31]);
924 st->cr();
926 }
927 void os::print_context(outputStream *st, void *context) {
928 if (context == NULL) return;
930 ucontext_t *uc = (ucontext_t*)context;
931 st->print_cr("Registers:");
932 st->print( "R0=" INTPTR_FORMAT, uc->uc_mcontext.gregs[0]);
933 st->print(", AT=" INTPTR_FORMAT, uc->uc_mcontext.gregs[1]);
934 st->print(", V0=" INTPTR_FORMAT, uc->uc_mcontext.gregs[2]);
935 st->print(", V1=" INTPTR_FORMAT, uc->uc_mcontext.gregs[3]);
936 st->cr();
937 st->print( "A0=" INTPTR_FORMAT, uc->uc_mcontext.gregs[4]);
938 st->print(", A1=" INTPTR_FORMAT, uc->uc_mcontext.gregs[5]);
939 st->print(", A2=" INTPTR_FORMAT, uc->uc_mcontext.gregs[6]);
940 st->print(", A3=" INTPTR_FORMAT, uc->uc_mcontext.gregs[7]);
941 st->cr();
942 st->print( "A4=" INTPTR_FORMAT, uc->uc_mcontext.gregs[8]);
943 st->print(", A5=" INTPTR_FORMAT, uc->uc_mcontext.gregs[9]);
944 st->print(", A6=" INTPTR_FORMAT, uc->uc_mcontext.gregs[10]);
945 st->print(", A7=" INTPTR_FORMAT, uc->uc_mcontext.gregs[11]);
946 st->cr();
947 st->print( "T0=" INTPTR_FORMAT, uc->uc_mcontext.gregs[12]);
948 st->print(", T1=" INTPTR_FORMAT, uc->uc_mcontext.gregs[13]);
949 st->print(", T2=" INTPTR_FORMAT, uc->uc_mcontext.gregs[14]);
950 st->print(", T3=" INTPTR_FORMAT, uc->uc_mcontext.gregs[15]);
951 st->cr();
952 st->print( "S0=" INTPTR_FORMAT, uc->uc_mcontext.gregs[16]);
953 st->print(", S1=" INTPTR_FORMAT, uc->uc_mcontext.gregs[17]);
954 st->print(", S2=" INTPTR_FORMAT, uc->uc_mcontext.gregs[18]);
955 st->print(", S3=" INTPTR_FORMAT, uc->uc_mcontext.gregs[19]);
956 st->cr();
957 st->print( "S4=" INTPTR_FORMAT, uc->uc_mcontext.gregs[20]);
958 st->print(", S5=" INTPTR_FORMAT, uc->uc_mcontext.gregs[21]);
959 st->print(", S6=" INTPTR_FORMAT, uc->uc_mcontext.gregs[22]);
960 st->print(", S7=" INTPTR_FORMAT, uc->uc_mcontext.gregs[23]);
961 st->cr();
962 st->print( "T8=" INTPTR_FORMAT, uc->uc_mcontext.gregs[24]);
963 st->print(", T9=" INTPTR_FORMAT, uc->uc_mcontext.gregs[25]);
964 st->print(", K0=" INTPTR_FORMAT, uc->uc_mcontext.gregs[26]);
965 st->print(", K1=" INTPTR_FORMAT, uc->uc_mcontext.gregs[27]);
966 st->cr();
967 st->print( "GP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[28]);
968 st->print(", SP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[29]);
969 st->print(", FP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[30]);
970 st->print(", RA=" INTPTR_FORMAT, uc->uc_mcontext.gregs[31]);
971 st->cr();
972 st->cr();
974 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
975 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
976 //print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
977 print_hex_dump(st, (address)sp-32, (address)(sp + 32), sizeof(intptr_t));
978 st->cr();
980 // Note: it may be unsafe to inspect memory near pc. For example, pc may
981 // point to garbage if entry point in an nmethod is corrupted. Leave
982 // this at the end, and hope for the best.
983 address pc = os::Linux::ucontext_get_pc(uc);
984 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
985 print_hex_dump(st, pc - 64, pc + 64, sizeof(char));
986 Disassembler::decode(pc - 80, pc + 80, st);
987 }
989 void os::setup_fpu() {
990 /*
991 //no use for MIPS
992 int fcsr;
993 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
994 __asm__ __volatile__ (
995 ".set noat;"
996 "cfc1 %0, $31;"
997 "sw %0, 0(%1);"
998 : "=r" (fcsr)
999 : "r" (fpu_cntrl)
1000 : "memory"
1001 );
1002 printf("fpu_cntrl: %lx\n", fpu_cntrl);
1003 */
1004 }
1006 #ifndef PRODUCT
1007 void os::verify_stack_alignment() {
1008 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
1009 }
1010 #endif
