static void print_bug_submit_message(outputStream *out, Thread *thread) {
if (out == NULL) return;
out->print_raw_cr("# If you would like to submit a bug report, please visit:");
out->print_raw ("# ");
out->print_raw_cr(Arguments::java_vendor_url_bug());
// If the crash is in native code, encourage user to submit a bug to the
// provider of that code.
if (thread && thread->is_Java_thread() &&
!thread->is_hidden_from_external_view()) {
JavaThread* jt = (JavaThread*)thread;
if (jt->thread_state() == _thread_in_native) {
out->print_cr("# The crash happened outside the Java Virtual Machine in native code.\n# See problematic frame for where to report the bug.");
}
}
out->print_raw_cr("#");
}
void ZeroStack::handle_overflow(TRAPS) {
JavaThread *thread = (JavaThread *) THREAD;
// Set up the frame anchor if it isn't already
bool has_last_Java_frame = thread->has_last_Java_frame();
if (!has_last_Java_frame) {
intptr_t *sp = thread->zero_stack()->sp();
ZeroFrame *frame = thread->top_zero_frame();
while (frame) {
if (frame->is_shark_frame())
break;
if (frame->is_interpreter_frame()) {
interpreterState istate =
frame->as_interpreter_frame()->interpreter_state();
if (istate->self_link() == istate)
break;
}
sp = ((intptr_t *) frame) + 1;
frame = frame->next();
}
if (frame == NULL)
fatal("unrecoverable stack overflow");
thread->set_last_Java_frame(frame, sp);
}
// Throw the exception
switch (thread->thread_state()) {
case _thread_in_Java:
InterpreterRuntime::throw_StackOverflowError(thread);
break;
case _thread_in_vm:
Exceptions::throw_stack_overflow_exception(thread, __FILE__, __LINE__);
break;
default:
ShouldNotReachHere();
}
// Reset the frame anchor if necessary
if (!has_last_Java_frame)
thread->reset_last_Java_frame();
}
int VM_Exit::set_vm_exited() {
Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
int num_active = 0;
_shutdown_thread = thr_cur;
_vm_exited = true; // global flag
for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())
if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
++num_active;
thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
}
return num_active;
}
int VM_Exit::set_vm_exited() {
CodeCacheExtensions::complete_step(CodeCacheExtensionsSteps::LastStep);
Thread * thr_cur = Thread::current();
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
int num_active = 0;
_shutdown_thread = thr_cur;
_vm_exited = true; // global flag
for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())
if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
++num_active;
thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
}
return num_active;
}
extern "C" JNIEXPORT int
JVM_handle_linux_signal(int sig,
siginfo_t* info,
void* ucVoid,
int abort_if_unrecognized) {
// in fact this isn't ucontext_t* at all, but struct sigcontext*
// but Linux porting layer uses ucontext_t, so to minimize code change
// we cast as needed
ucontext_t* ucFake = (ucontext_t*) ucVoid;
sigcontext* uc = (sigcontext*)ucVoid;
Thread* t = ThreadLocalStorage::get_thread_slow();
SignalHandlerMark shm(t);
// Note: it's not uncommon that JNI code uses signal/sigset to install
// then restore certain signal handler (e.g. to temporarily block SIGPIPE,
// or have a SIGILL handler when detecting CPU type). When that happens,
// JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
// avoid unnecessary crash when libjsig is not preloaded, try handle signals
// that do not require siginfo/ucontext first.
if (sig == SIGPIPE || sig == SIGXFSZ) {
// allow chained handler to go first
if (os::Linux::chained_handler(sig, info, ucVoid)) {
return true;
} else {
if (PrintMiscellaneous && (WizardMode || Verbose)) {
char buf[64];
warning("Ignoring %s - see bugs 4229104 or 646499219",
os::exception_name(sig, buf, sizeof(buf)));
}
return true;
}
}
JavaThread* thread = NULL;
VMThread* vmthread = NULL;
if (os::Linux::signal_handlers_are_installed) {
if (t != NULL ){
if(t->is_Java_thread()) {
thread = (JavaThread*)t;
}
else if(t->is_VM_thread()){
vmthread = (VMThread *)t;
}
}
}
// decide if this trap can be handled by a stub
address stub = NULL;
address pc = NULL;
address npc = NULL;
//%note os_trap_1
if (info != NULL && uc != NULL && thread != NULL) {
pc = address(SIG_PC(uc));
npc = address(SIG_NPC(uc));
// Check to see if we caught the safepoint code in the
// process of write protecting the memory serialization page.
// It write enables the page immediately after protecting it
// so we can just return to retry the write.
if ((sig == SIGSEGV) && checkSerializePage(thread, (address)info->si_addr)) {
// Block current thread until the memory serialize page permission restored.
os::block_on_serialize_page_trap();
return 1;
}
if (checkPrefetch(uc, pc)) {
return 1;
}
// Handle ALL stack overflow variations here
if (sig == SIGSEGV) {
if (checkOverflow(uc, pc, (address)info->si_addr, thread, &stub)) {
return 1;
}
}
if (sig == SIGBUS &&
thread->thread_state() == _thread_in_vm &&
thread->doing_unsafe_access()) {
stub = StubRoutines::handler_for_unsafe_access();
}
if (thread->thread_state() == _thread_in_Java) {
do {
// Java thread running in Java code => find exception handler if any
// a fault inside compiled code, the interpreter, or a stub
if ((sig == SIGSEGV) && checkPollingPage(pc, (address)info->si_addr, &stub)) {
break;
}
if ((sig == SIGBUS) && checkByteBuffer(pc, &stub)) {
break;
}
if ((sig == SIGSEGV || sig == SIGBUS) &&
checkVerifyOops(pc, (address)info->si_addr, &stub)) {
break;
}
if ((sig == SIGSEGV) && checkZombie(uc, &pc, &stub)) {
break;
}
if ((sig == SIGILL) && checkICMiss(uc, &pc, &stub)) {
break;
}
if ((sig == SIGFPE) && checkFPFault(pc, info->si_code, thread, &stub)) {
break;
}
if ((sig == SIGSEGV) &&
checkNullPointer(pc, (intptr_t)info->si_addr, thread, &stub)) {
break;
}
} while (0);
// jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
// and the heap gets shrunk before the field access.
if ((sig == SIGSEGV) || (sig == SIGBUS)) {
checkFastJNIAccess(pc, &stub);
}
}
if (stub != NULL) {
// save all thread context in case we need to restore it
thread->set_saved_exception_pc(pc);
thread->set_saved_exception_npc(npc);
set_cont_address(uc, stub);
return true;
}
}
// signal-chaining
if (os::Linux::chained_handler(sig, info, ucVoid)) {
return true;
}
if (!abort_if_unrecognized) {
// caller wants another chance, so give it to him
return false;
}
if (pc == NULL && uc != NULL) {
pc = os::Linux::ucontext_get_pc((ucontext_t*)uc);
}
// unmask current signal
sigset_t newset;
sigemptyset(&newset);
sigaddset(&newset, sig);
sigprocmask(SIG_UNBLOCK, &newset, NULL);
VMError err(t, sig, pc, info, ucVoid);
err.report_and_die();
ShouldNotReachHere();
}
inline bool vframeStreamCommon::fill_from_frame() {
// Interpreted frame
if (_frame.is_interpreted_frame()) {
fill_from_interpreter_frame();
return true;
}
// Compiled frame
if (cb() != NULL && cb()->is_nmethod()) {
if (nm()->is_native_method()) {
// Do not rely on scopeDesc since the pc might be unprecise due to the _last_native_pc trick.
fill_from_compiled_native_frame();
} else {
PcDesc* pc_desc = nm()->pc_desc_at(_frame.pc());
int decode_offset;
if (pc_desc == NULL) {
// Should not happen, but let fill_from_compiled_frame handle it.
// If we are trying to walk the stack of a thread that is not
// at a safepoint (like AsyncGetCallTrace would do) then this is an
// acceptable result. [ This is assuming that safe_for_sender
// is so bullet proof that we can trust the frames it produced. ]
//
// So if we see that the thread is not safepoint safe
// then simply produce the method and a bci of zero
// and skip the possibility of decoding any inlining that
// may be present. That is far better than simply stopping (or
// asserting. If however the thread is safepoint safe this
// is the sign of a compiler bug and we'll let
// fill_from_compiled_frame handle it.
JavaThreadState state = _thread->thread_state();
// in_Java should be good enough to test safepoint safety
// if state were say in_Java_trans then we'd expect that
// the pc would have already been slightly adjusted to
// one that would produce a pcDesc since the trans state
// would be one that might in fact anticipate a safepoint
if (state == _thread_in_Java ) {
// This will get a method a zero bci and no inlining.
// Might be nice to have a unique bci to signify this
// particular case but for now zero will do.
fill_from_compiled_native_frame();
// There is something to be said for setting the mode to
// at_end_mode to prevent trying to walk further up the
// stack. There is evidence that if we walk any further
// that we could produce a bad stack chain. However until
// we see evidence that allowing this causes us to find
// frames bad enough to cause segv's or assertion failures
// we don't do it as while we may get a bad call chain the
// probability is much higher (several magnitudes) that we
// get good data.
return true;
}
decode_offset = DebugInformationRecorder::serialized_null;
} else {
decode_offset = pc_desc->scope_decode_offset();
}
fill_from_compiled_frame(decode_offset);
}
return true;
}
// End of stack?
if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) {
_mode = at_end_mode;
return true;
}
return false;
}
// For Forte Analyzer AsyncGetCallTrace profiling support - thread is
// currently interrupted by SIGPROF
bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
void* ucontext,
bool isInJava) {
assert(Thread::current() == this, "caller must be current thread");
assert(this->is_Java_thread(), "must be JavaThread");
JavaThread* jt = (JavaThread *)this;
if (!isInJava) {
// make_walkable flushes register windows and grabs last_Java_pc
// which can not be done if the ucontext sp matches last_Java_sp
// stack walking utilities assume last_Java_pc set if marked flushed
jt->frame_anchor()->make_walkable(jt);
}
// If we have a walkable last_Java_frame, then we should use it
// even if isInJava == true. It should be more reliable than
// ucontext info.
if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
*fr_addr = jt->pd_last_frame();
return true;
}
ucontext_t* uc = (ucontext_t*) ucontext;
// At this point, we don't have a walkable last_Java_frame, so
// we try to glean some information out of the ucontext.
intptr_t* ret_sp;
ExtendedPC addr =
os::fetch_frame_from_context(uc, &ret_sp,
NULL /* ret_fp only used on X86 */);
if (addr.pc() == NULL || ret_sp == NULL) {
// ucontext wasn't useful
return false;
}
#if INCLUDE_CDS
if (UseSharedSpaces && MetaspaceShared::is_in_shared_region(addr.pc(), MetaspaceShared::md)) {
// In the middle of a trampoline call. Bail out for safety.
// This happens rarely so shouldn't affect profiling.
return false;
}
#endif
// we were running Java code when SIGPROF came in
if (isInJava) {
// If we have a last_Java_sp, then the SIGPROF signal caught us
// right when we were transitioning from _thread_in_Java to a new
// JavaThreadState. We use last_Java_sp instead of the sp from
// the ucontext since it should be more reliable.
if (jt->has_last_Java_frame()) {
ret_sp = jt->last_Java_sp();
}
// Implied else: we don't have a last_Java_sp so we use what we
// got from the ucontext.
frame ret_frame(ret_sp, frame::unpatchable, addr.pc());
if (!ret_frame.safe_for_sender(jt)) {
// nothing else to try if the frame isn't good
return false;
}
*fr_addr = ret_frame;
return true;
}
// At this point, we know we weren't running Java code. We might
// have a last_Java_sp, but we don't have a walkable frame.
// However, we might still be able to construct something useful
// if the thread was running native code.
if (jt->has_last_Java_frame()) {
assert(!jt->frame_anchor()->walkable(), "case covered above");
if (jt->thread_state() == _thread_in_native) {
frame ret_frame(jt->last_Java_sp(), frame::unpatchable, addr.pc());
if (!ret_frame.safe_for_sender(jt)) {
// nothing else to try if the frame isn't good
return false;
}
*fr_addr = ret_frame;
return true;
}
}
// nothing else to try
return false;
}
extern "C" JNIEXPORT int
JVM_handle_linux_signal(int sig,
siginfo_t* info,
void* ucVoid,
int abort_if_unrecognized) {
ucontext_t* uc = (ucontext_t*) ucVoid;
Thread* t = ThreadLocalStorage::get_thread_slow();
SignalHandlerMark shm(t);
// Note: it's not uncommon that JNI code uses signal/sigset to
// install then restore certain signal handler (e.g. to temporarily
// block SIGPIPE, or have a SIGILL handler when detecting CPU
// type). When that happens, JVM_handle_linux_signal() might be
// invoked with junk info/ucVoid. To avoid unnecessary crash when
// libjsig is not preloaded, try handle signals that do not require
// siginfo/ucontext first.
if (sig == SIGPIPE || sig == SIGXFSZ) {
// allow chained handler to go first
if (os::Linux::chained_handler(sig, info, ucVoid)) {
return true;
} else {
if (PrintMiscellaneous && (WizardMode || Verbose)) {
char buf[64];
warning("Ignoring %s - see bugs 4229104 or 646499219",
os::exception_name(sig, buf, sizeof(buf)));
}
return true;
}
}
JavaThread* thread = NULL;
VMThread* vmthread = NULL;
if (os::Linux::signal_handlers_are_installed) {
if (t != NULL ){
if(t->is_Java_thread()) {
thread = (JavaThread*)t;
}
else if(t->is_VM_thread()){
vmthread = (VMThread *)t;
}
}
}
if (info != NULL && thread != NULL) {
// Handle ALL stack overflow variations here
if (sig == SIGSEGV) {
address addr = (address) info->si_addr;
// check if fault address is within thread stack
if (addr < thread->stack_base() &&
addr >= thread->stack_base() - thread->stack_size()) {
// stack overflow
if (thread->in_stack_yellow_zone(addr)) {
thread->disable_stack_yellow_zone();
ShouldNotCallThis();
}
else if (thread->in_stack_red_zone(addr)) {
thread->disable_stack_red_zone();
ShouldNotCallThis();
}
else {
// Accessing stack address below sp may cause SEGV if
// current thread has MAP_GROWSDOWN stack. This should
// only happen when current thread was created by user
// code with MAP_GROWSDOWN flag and then attached to VM.
// See notes in os_linux.cpp.
if (thread->osthread()->expanding_stack() == 0) {
thread->osthread()->set_expanding_stack();
if (os::Linux::manually_expand_stack(thread, addr)) {
thread->osthread()->clear_expanding_stack();
return true;
}
thread->osthread()->clear_expanding_stack();
}
else {
fatal("recursive segv. expanding stack.");
}
}
}
}
/*if (thread->thread_state() == _thread_in_Java) {
ShouldNotCallThis();
}
else*/ if (thread->thread_state() == _thread_in_vm &&
sig == SIGBUS && thread->doing_unsafe_access()) {
ShouldNotCallThis();
}
// jni_fast_Get<Primitive>Field can trap at certain pc's if a GC
// kicks in and the heap gets shrunk before the field access.
/*if (sig == SIGSEGV || sig == SIGBUS) {
address addr = JNI_FastGetField::find_slowcase_pc(pc);
if (addr != (address)-1) {
stub = addr;
}
}*/
// Check to see if we caught the safepoint code in the process
// of write protecting the memory serialization page. It write
// enables the page immediately after protecting it so we can
// just return to retry the write.
if (sig == SIGSEGV &&
os::is_memory_serialize_page(thread, (address) info->si_addr)) {
// Block current thread until permission is restored.
os::block_on_serialize_page_trap();
return true;
}
}
// signal-chaining
if (os::Linux::chained_handler(sig, info, ucVoid)) {
return true;
}
if (!abort_if_unrecognized) {
// caller wants another chance, so give it to him
return false;
}
#ifndef PRODUCT
if (sig == SIGSEGV) {
fatal("\n#"
"\n# /--------------------\\"
"\n# | segmentation fault |"
"\n# \\---\\ /--------------/"
"\n# /"
"\n# [-] |\\_/| "
"\n# (+)=C |o o|__ "
"\n# | | =-*-=__\\ "
"\n# OOO c_c_(___)");
}
#endif // !PRODUCT
const char *fmt = "caught unhandled signal %d";
char buf[64];
sprintf(buf, fmt, sig);
fatal(buf);
}
void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
// This is if'd out because we no longer use thread suspension.
// However if someone wanted to backport this to a 5.0 jvm then this
// code would be important.
#if 0
if (SafepointSynchronize::is_synchronizing()) {
// The safepoint mechanism is trying to synchronize all the threads.
// Since this can involve thread suspension, it is not safe for us
// to be here. We can reduce the deadlock risk window by quickly
// returning to the SIGPROF handler. However, it is still possible
// for VMThread to catch us here or in the SIGPROF handler. If we
// are suspended while holding a resource and another thread blocks
// on that resource in the SIGPROF handler, then we will have a
// three-thread deadlock (VMThread, this thread, the other thread).
trace->num_frames = ticks_safepoint; // -10
return;
}
#endif
JavaThread* thread;
if (trace->env_id == NULL ||
(thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
thread->is_exiting()) {
// bad env_id, thread has exited or thread is exiting
trace->num_frames = ticks_thread_exit; // -8
return;
}
if (thread->in_deopt_handler()) {
// thread is in the deoptimization handler so return no frames
trace->num_frames = ticks_deopt; // -9
return;
}
assert(JavaThread::current() == thread,
"AsyncGetCallTrace must be called by the current interrupted thread");
if (!JvmtiExport::should_post_class_load()) {
trace->num_frames = ticks_no_class_load; // -1
return;
}
if (Universe::heap()->is_gc_active()) {
trace->num_frames = ticks_GC_active; // -2
return;
}
switch (thread->thread_state()) {
case _thread_new:
case _thread_uninitialized:
case _thread_new_trans:
// We found the thread on the threads list above, but it is too
// young to be useful so return that there are no Java frames.
trace->num_frames = 0;
break;
case _thread_in_native:
case _thread_in_native_trans:
case _thread_blocked:
case _thread_blocked_trans:
case _thread_in_vm:
case _thread_in_vm_trans:
{
frame fr;
// param isInJava == false - indicate we aren't in Java code
if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame
} else {
if (!thread->has_last_Java_frame()) {
trace->num_frames = 0; // No Java frames
} else {
trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default
forte_fill_call_trace_given_top(thread, trace, depth, fr);
// This assert would seem to be valid but it is not.
// It would be valid if we weren't possibly racing a gc
// thread. A gc thread can make a valid interpreted frame
// look invalid. It's a small window but it does happen.
// The assert is left here commented out as a reminder.
// assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");
}
}
}
break;
case _thread_in_Java:
case _thread_in_Java_trans:
{
frame fr;
// param isInJava == true - indicate we are in Java code
if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
trace->num_frames = ticks_unknown_Java; // -5 unknown frame
} else {
trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default
forte_fill_call_trace_given_top(thread, trace, depth, fr);
}
}
break;
default:
// Unknown thread state
trace->num_frames = ticks_unknown_state; // -7
break;
}
}
JNIEXPORT
void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
JavaThread* thread;
if (trace->env_id == NULL ||
(thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
thread->is_exiting()) {
// bad env_id, thread has exited or thread is exiting
trace->num_frames = ticks_thread_exit; // -8
return;
}
if (thread->in_deopt_handler()) {
// thread is in the deoptimization handler so return no frames
trace->num_frames = ticks_deopt; // -9
return;
}
assert(JavaThread::current() == thread,
"AsyncGetCallTrace must be called by the current interrupted thread");
if (!JvmtiExport::should_post_class_load()) {
trace->num_frames = ticks_no_class_load; // -1
return;
}
if (Universe::heap()->is_gc_active()) {
trace->num_frames = ticks_GC_active; // -2
return;
}
switch (thread->thread_state()) {
case _thread_new:
case _thread_uninitialized:
case _thread_new_trans:
// We found the thread on the threads list above, but it is too
// young to be useful so return that there are no Java frames.
trace->num_frames = 0;
break;
case _thread_in_native:
case _thread_in_native_trans:
case _thread_blocked:
case _thread_blocked_trans:
case _thread_in_vm:
case _thread_in_vm_trans:
{
frame fr;
// param isInJava == false - indicate we aren't in Java code
if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame
} else {
if (!thread->has_last_Java_frame()) {
trace->num_frames = 0; // No Java frames
} else {
trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default
forte_fill_call_trace_given_top(thread, trace, depth, fr);
// This assert would seem to be valid but it is not.
// It would be valid if we weren't possibly racing a gc
// thread. A gc thread can make a valid interpreted frame
// look invalid. It's a small window but it does happen.
// The assert is left here commented out as a reminder.
// assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");
}
}
}
break;
case _thread_in_Java:
case _thread_in_Java_trans:
{
frame fr;
// param isInJava == true - indicate we are in Java code
if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
trace->num_frames = ticks_unknown_Java; // -5 unknown frame
} else {
trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default
forte_fill_call_trace_given_top(thread, trace, depth, fr);
}
}
break;
default:
// Unknown thread state
trace->num_frames = ticks_unknown_state; // -7
break;
}
}
extern "C" JNIEXPORT int
JVM_handle_linux_signal(int sig,
siginfo_t* info,
void* ucVoid,
int abort_if_unrecognized) {
ucontext_t* uc = (ucontext_t*) ucVoid;
Thread* t = ThreadLocalStorage::get_thread_slow();
// Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
// (no destructors can be run)
os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
SignalHandlerMark shm(t);
// Note: it's not uncommon that JNI code uses signal/sigset to install
// then restore certain signal handler (e.g. to temporarily block SIGPIPE,
// or have a SIGILL handler when detecting CPU type). When that happens,
// JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
// avoid unnecessary crash when libjsig is not preloaded, try handle signals
// that do not require siginfo/ucontext first.
if (sig == SIGPIPE || sig == SIGXFSZ) {
// allow chained handler to go first
if (os::Linux::chained_handler(sig, info, ucVoid)) {
return true;
} else {
if (PrintMiscellaneous && (WizardMode || Verbose)) {
char buf[64];
warning("Ignoring %s - see bugs 4229104 or 646499219",
os::exception_name(sig, buf, sizeof(buf)));
}
return true;
}
}
JavaThread* thread = NULL;
VMThread* vmthread = NULL;
if (os::Linux::signal_handlers_are_installed) {
if (t != NULL ){
if(t->is_Java_thread()) {
thread = (JavaThread*)t;
}
else if(t->is_VM_thread()){
vmthread = (VMThread *)t;
}
}
}
/*
NOTE: does not seem to work on linux.
if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
// can't decode this kind of signal
info = NULL;
} else {
assert(sig == info->si_signo, "bad siginfo");
}
*/
// decide if this trap can be handled by a stub
address stub = NULL;
address pc = NULL;
//%note os_trap_1
if (info != NULL && uc != NULL && thread != NULL) {
pc = (address) os::Linux::ucontext_get_pc(uc);
#ifdef BUILTIN_SIM
if (pc == (address) Fetch32PFI) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
return 1 ;
}
if (pc == (address) FetchNPFI) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ;
return 1 ;
}
#else
if (StubRoutines::is_safefetch_fault(pc)) {
uc->uc_mcontext.pc = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
return 1;
}
#endif
#ifndef AMD64
// Halt if SI_KERNEL before more crashes get misdiagnosed as Java bugs
// This can happen in any running code (currently more frequently in
// interpreter code but has been seen in compiled code)
if (sig == SIGSEGV && info->si_addr == 0 && info->si_code == SI_KERNEL) {
fatal("An irrecoverable SI_KERNEL SIGSEGV has occurred due "
"to unstable signal handling in this distribution.");
}
#endif // AMD64
// Handle ALL stack overflow variations here
if (sig == SIGSEGV) {
address addr = (address) info->si_addr;
// check if fault address is within thread stack
if (addr < thread->stack_base() &&
addr >= thread->stack_base() - thread->stack_size()) {
// stack overflow
if (thread->in_stack_yellow_zone(addr)) {
thread->disable_stack_yellow_zone();
if (thread->thread_state() == _thread_in_Java) {
// Throw a stack overflow exception. Guard pages will be reenabled
// while unwinding the stack.
stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
} else {
// Thread was in the vm or native code. Return and try to finish.
return 1;
}
} else if (thread->in_stack_red_zone(addr)) {
// Fatal red zone violation. Disable the guard pages and fall through
// to handle_unexpected_exception way down below.
thread->disable_stack_red_zone();
tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
// This is a likely cause, but hard to verify. Let's just print
// it as a hint.
tty->print_raw_cr("Please check if any of your loaded .so files has "
"enabled executable stack (see man page execstack(8))");
} else {
// Accessing stack address below sp may cause SEGV if current
// thread has MAP_GROWSDOWN stack. This should only happen when
// current thread was created by user code with MAP_GROWSDOWN flag
// and then attached to VM. See notes in os_linux.cpp.
if (thread->osthread()->expanding_stack() == 0) {
thread->osthread()->set_expanding_stack();
if (os::Linux::manually_expand_stack(thread, addr)) {
thread->osthread()->clear_expanding_stack();
return 1;
}
thread->osthread()->clear_expanding_stack();
} else {
fatal("recursive segv. expanding stack.");
}
}
}
}
if (thread->thread_state() == _thread_in_Java) {
// Java thread running in Java code => find exception handler if any
// a fault inside compiled code, the interpreter, or a stub
// Handle signal from NativeJump::patch_verified_entry().
if ((sig == SIGILL || sig == SIGTRAP)
&& nativeInstruction_at(pc)->is_sigill_zombie_not_entrant()) {
if (TraceTraps) {
tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
}
stub = SharedRuntime::get_handle_wrong_method_stub();
} else if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
stub = SharedRuntime::get_poll_stub(pc);
} else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
// BugId 4454115: A read from a MappedByteBuffer can fault
// here if the underlying file has been truncated.
// Do not crash the VM in such a case.
CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL;
if (nm != NULL && nm->has_unsafe_access()) {
stub = handle_unsafe_access(thread, pc);
}
}
else
if (sig == SIGFPE &&
(info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
stub =
SharedRuntime::
continuation_for_implicit_exception(thread,
pc,
SharedRuntime::
IMPLICIT_DIVIDE_BY_ZERO);
} else if (sig == SIGSEGV &&
!MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
// Determination of interpreter/vtable stub/compiled code null exception
stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
}
} else if (thread->thread_state() == _thread_in_vm &&
sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
thread->doing_unsafe_access()) {
stub = handle_unsafe_access(thread, pc);
}
// jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
// and the heap gets shrunk before the field access.
if ((sig == SIGSEGV) || (sig == SIGBUS)) {
address addr = JNI_FastGetField::find_slowcase_pc(pc);
if (addr != (address)-1) {
stub = addr;
}
}
// Check to see if we caught the safepoint code in the
// process of write protecting the memory serialization page.
// It write enables the page immediately after protecting it
// so we can just return to retry the write.
if ((sig == SIGSEGV) &&
os::is_memory_serialize_page(thread, (address) info->si_addr)) {
// Block current thread until the memory serialize page permission restored.
os::block_on_serialize_page_trap();
return true;
}
}
if (stub != NULL) {
// save all thread context in case we need to restore it
if (thread != NULL) thread->set_saved_exception_pc(pc);
#ifdef BUILTIN_SIM
uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
#else
uc->uc_mcontext.pc = (__u64)stub;
#endif
return true;
}
// signal-chaining
if (os::Linux::chained_handler(sig, info, ucVoid)) {
return true;
}
if (!abort_if_unrecognized) {
// caller wants another chance, so give it to him
return false;
}
if (pc == NULL && uc != NULL) {
pc = os::Linux::ucontext_get_pc(uc);
}
// unmask current signal
sigset_t newset;
sigemptyset(&newset);
sigaddset(&newset, sig);
sigprocmask(SIG_UNBLOCK, &newset, NULL);
VMError err(t, sig, pc, info, ucVoid);
err.report_and_die();
ShouldNotReachHere();
}
