// 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;
// last_Java_frame is always walkable and safe use it if we have it
if (jt->has_last_Java_frame()) {
*fr_addr = jt->pd_last_frame();
return true;
}
ucontext_t* uc = (ucontext_t*) ucontext;
// We always want to use the initial frame we create from the ucontext as
// it certainly signals where we currently are. However that frame may not
// be safe for calling sender. In that case if we have a last_Java_frame
// then the forte walker will switch to that frame as the virtual sender
// for the frame we create here which is not sender safe.
intptr_t* ret_fp;
intptr_t* ret_sp;
ExtendedPC addr = os::Solaris::fetch_frame_from_ucontext(this, uc, &ret_sp, &ret_fp);
// Something would really have to be screwed up to get a NULL pc
if (addr.pc() == NULL ) {
assert(false, "NULL pc from signal handler!");
return false;
}
// If sp and fp are nonsense just leave them out
if ((address)ret_sp >= jt->stack_base() ||
(address)ret_sp < jt->stack_base() - jt->stack_size() ) {
ret_sp = NULL;
ret_fp = NULL;
} else {
// sp is reasonable is fp reasonable?
if ( (address)ret_fp >= jt->stack_base() || ret_fp < ret_sp) {
ret_fp = NULL;
}
}
frame ret_frame(ret_sp, ret_fp, addr.pc());
*fr_addr = ret_frame;
return true;
}
// Reduce the guard page by YellowZonePages to allow for the processing
// of register stack overflow exceptions.
void JavaThread::disable_register_stack_guard() {
address reg_stk_limit;
JavaThread* thread = (JavaThread *)Thread::current();
assert(thread != NULL,"Sanity check");
if ( !thread->is_Java_thread() ) return;
// We assume that the register stack is the same size as the memory stack and that
// it starts at the beginning stack address and grows higher. The memory stack
// grows to lower addresses.
reg_stk_limit = thread->stack_base() + thread->stack_size() -
((StackShadowPages + StackRedPages) * os::vm_page_size());
thread->set_register_stack_limit( reg_stk_limit );
}
// Check to see if the current BSP is within our current guard
// page area.
bool JavaThread::register_stack_overflow() {
address reg_stk_limit;
JavaThread* thread = (JavaThread *)Thread::current();
assert(thread != NULL,"Sanity check");
if ( !thread->is_Java_thread() ) return false;
reg_stk_limit = thread->stack_base() + thread->stack_size() -
((StackShadowPages + StackYellowPages +
StackRedPages) * os::vm_page_size());
if ( StubRoutines::ia64::get_backing_store_pointer() > reg_stk_limit )
return true;
else
return false;
}
// OS specific thread initialization
//
// For Itanium, we calculate and store the limits of the
// register and memory stacks.
//
void os::initialize_thread() {
address mem_stk_limit;
JavaThread* thread = (JavaThread *)Thread::current();
assert(thread != NULL,"Sanity check");
if ( !thread->is_Java_thread() ) return;
// Initialize our register stack limit which is our guard
JavaThread::enable_register_stack_guard();
// Initialize our memory stack limit
mem_stk_limit = thread->stack_base() - thread->stack_size() +
((StackShadowPages + StackYellowPages +
StackRedPages) * os::vm_page_size());
thread->set_memory_stack_limit( mem_stk_limit );
}
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);
}
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();
}
// The call stub is used to call Java from C
static void call_stub(
JavaCallWrapper *call_wrapper,
intptr_t* result,
BasicType result_type,
methodOop method,
address entry_point,
intptr_t* parameters,
int parameter_words,
TRAPS) {
JavaThread *thread = (JavaThread *) THREAD;
ZeroStack *stack = thread->zero_stack();
// Make sure we have no pending exceptions
assert(!HAS_PENDING_EXCEPTION, "call_stub called with pending exception");
// Set up the stack if necessary
bool stack_needs_teardown = false;
if (stack->needs_setup()) {
size_t stack_used = thread->stack_base() - (address) &stack_used;
size_t stack_free = thread->stack_size() - stack_used;
size_t zero_stack_size = align_size_down(stack_free / 2, wordSize);
stack->setup(alloca(zero_stack_size), zero_stack_size);
stack_needs_teardown = true;
}
// Allocate and initialize our frame
thread->push_zero_frame(
EntryFrame::build(stack, parameters, parameter_words, call_wrapper));
// Make the call
Interpreter::invoke_method(method, entry_point, THREAD);
// Store result depending on type
if (!HAS_PENDING_EXCEPTION) {
switch (result_type) {
case T_INT:
*(jint *) result = *(jint *) stack->sp();
break;
case T_LONG:
*(jlong *) result = *(jlong *) stack->sp();
break;
case T_FLOAT:
*(jfloat *) result = *(jfloat *) stack->sp();
break;
case T_DOUBLE:
*(jdouble *) result = *(jdouble *) stack->sp();
break;
case T_OBJECT:
*(oop *) result = *(oop *) stack->sp();
break;
default:
ShouldNotReachHere();
}
}
// Unwind our frame
thread->pop_zero_frame();
// Tear down the stack if necessary
if (stack_needs_teardown)
stack->teardown();
}
