bool vframeStream::fill_from_frame() {
// Interpreted frame
if (_frame.is_interpreted_frame()) {
fill_from_interpreter_frame();
return true;
}
// Compiled frame
#ifndef CORE
CodeBlob* code = CodeCache::find_blob(_frame.pc());
if (code != NULL && code->is_nmethod()) {
nmethod* nm = (nmethod*)code;
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(nm);
} else {
bool at_call = _reg_map.is_pc_at_call(_frame.id());
PcDesc* pc_desc = nm->pc_desc_at(_frame.pc(), at_call);
#ifdef ASSERT
if (pc_desc == NULL) {
tty->print_cr("Error in fill_from_frame: pc_desc for " INTPTR_FORMAT " not found", _frame.pc());
nm->print();
nm->method()->print_codes();
nm->print_code();
nm->print_pcs();
}
#endif
assert(pc_desc != NULL, "scopeDesc must exist");
fill_from_compiled_frame(nm, pc_desc->scope_decode_offset());
}
return true;
}
#endif
// End of stack?
if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) {
_mode = at_end_mode;
return true;
}
// Deoptimized frame
#ifndef CORE
if (_frame.is_deoptimized_frame()) {
fill_from_deoptimized_frame(_thread->vframe_array_for(&_frame), vframeArray::first_index());
return true;
}
#endif
return false;
}
inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) {
_mode = compiled_mode;
// Range check to detect ridiculous offsets.
if (decode_offset == DebugInformationRecorder::serialized_null ||
decode_offset < 0 ||
decode_offset >= nm()->scopes_data_size()) {
// 6379830 AsyncGetCallTrace sometimes feeds us wild frames.
// If we attempt to read nmethod::scopes_data at serialized_null (== 0),
// or if we read some at other crazy offset,
// we will decode garbage and make wild references into the heap,
// leading to crashes in product mode.
// (This isn't airtight, of course, since there are internal
// offsets which are also crazy.)
#ifdef ASSERT
if (WizardMode) {
tty->print_cr("Error in fill_from_frame: pc_desc for "
INTPTR_FORMAT " not found or invalid at %d",
_frame.pc(), decode_offset);
nm()->print();
nm()->method()->print_codes();
nm()->print_code();
nm()->print_pcs();
}
#endif
// Provide a cheap fallback in product mode. (See comment above.)
found_bad_method_frame();
fill_from_compiled_native_frame();
return;
}
// Decode first part of scopeDesc
DebugInfoReadStream buffer(nm(), decode_offset);
_sender_decode_offset = buffer.read_int();
_method = methodOop(buffer.read_oop());
_bci = buffer.read_bci();
assert(_method->is_method(), "checking type of decoded method");
}
inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) {
_mode = compiled_mode;
// Range check to detect ridiculous offsets.
if (decode_offset == DebugInformationRecorder::serialized_null ||
decode_offset < 0 ||
decode_offset >= nm()->scopes_data_size()) {
// 6379830 AsyncGetCallTrace sometimes feeds us wild frames.
// If we read nmethod::scopes_data at serialized_null (== 0)
// or if read some at other invalid offset, invalid values will be decoded.
// Based on these values, invalid heap locations could be referenced
// that could lead to crashes in product mode.
// Therefore, do not use the decode offset if invalid, but fill the frame
// as it were a native compiled frame (no Java-level assumptions).
#ifdef ASSERT
if (WizardMode) {
tty->print_cr("Error in fill_from_frame: pc_desc for "
INTPTR_FORMAT " not found or invalid at %d",
p2i(_frame.pc()), decode_offset);
nm()->print();
nm()->method()->print_codes();
nm()->print_code();
nm()->print_pcs();
}
#endif
// Provide a cheap fallback in product mode. (See comment above.)
found_bad_method_frame();
fill_from_compiled_native_frame();
return;
}
// Decode first part of scopeDesc
DebugInfoReadStream buffer(nm(), decode_offset);
_sender_decode_offset = buffer.read_int();
_method = buffer.read_method();
_bci = buffer.read_bci();
assert(_method->is_method(), "checking type of decoded method");
}
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;
}
