Java example source code file (frame_x86.cpp)
The frame_x86.cpp Java example source code/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
#include "precompiled.hpp"
#include "interpreter/interpreter.hpp"
#include "memory/resourceArea.hpp"
#include "oops/markOop.hpp"
#include "oops/method.hpp"
#include "oops/oop.inline.hpp"
#include "prims/methodHandles.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/monitorChunk.hpp"
#include "runtime/os.hpp"
#include "runtime/signature.hpp"
#include "runtime/stubCodeGenerator.hpp"
#include "runtime/stubRoutines.hpp"
#include "vmreg_x86.inline.hpp"
#ifdef COMPILER1
#include "c1/c1_Runtime1.hpp"
#include "runtime/vframeArray.hpp"
#endif
#ifdef ASSERT
void RegisterMap::check_location_valid() {
}
#endif
// Profiling/safepoint support
bool frame::safe_for_sender(JavaThread *thread) {
address sp = (address)_sp;
address fp = (address)_fp;
address unextended_sp = (address)_unextended_sp;
// consider stack guards when trying to determine "safe" stack pointers
static size_t stack_guard_size = os::uses_stack_guard_pages() ? (StackYellowPages + StackRedPages) * os::vm_page_size() : 0;
size_t usable_stack_size = thread->stack_size() - stack_guard_size;
// sp must be within the usable part of the stack (not in guards)
bool sp_safe = (sp < thread->stack_base()) &&
(sp >= thread->stack_base() - usable_stack_size);
if (!sp_safe) {
return false;
}
// unextended sp must be within the stack and above or equal sp
bool unextended_sp_safe = (unextended_sp < thread->stack_base()) &&
(unextended_sp >= sp);
if (!unextended_sp_safe) {
return false;
}
// an fp must be within the stack and above (but not equal) sp
// second evaluation on fp+ is added to handle situation where fp is -1
bool fp_safe = (fp < thread->stack_base() && (fp > sp) && (((fp + (return_addr_offset * sizeof(void*))) < thread->stack_base())));
// We know sp/unextended_sp are safe only fp is questionable here
// If the current frame is known to the code cache then we can attempt to
// to construct the sender and do some validation of it. This goes a long way
// toward eliminating issues when we get in frame construction code
if (_cb != NULL ) {
// First check if frame is complete and tester is reliable
// Unfortunately we can only check frame complete for runtime stubs and nmethod
// other generic buffer blobs are more problematic so we just assume they are
// ok. adapter blobs never have a frame complete and are never ok.
if (!_cb->is_frame_complete_at(_pc)) {
if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
return false;
}
}
// Could just be some random pointer within the codeBlob
if (!_cb->code_contains(_pc)) {
return false;
}
// Entry frame checks
if (is_entry_frame()) {
// an entry frame must have a valid fp.
if (!fp_safe) return false;
// Validate the JavaCallWrapper an entry frame must have
address jcw = (address)entry_frame_call_wrapper();
bool jcw_safe = (jcw < thread->stack_base()) && ( jcw > fp);
return jcw_safe;
}
intptr_t* sender_sp = NULL;
address sender_pc = NULL;
if (is_interpreted_frame()) {
// fp must be safe
if (!fp_safe) {
return false;
}
sender_pc = (address) this->fp()[return_addr_offset];
sender_sp = (intptr_t*) addr_at(sender_sp_offset);
} else {
// must be some sort of compiled/runtime frame
// fp does not have to be safe (although it could be check for c1?)
// check for a valid frame_size, otherwise we are unlikely to get a valid sender_pc
if (_cb->frame_size() <= 0) {
return false;
}
sender_sp = _unextended_sp + _cb->frame_size();
// On Intel the return_address is always the word on the stack
sender_pc = (address) *(sender_sp-1);
}
// If the potential sender is the interpreter then we can do some more checking
if (Interpreter::contains(sender_pc)) {
// ebp is always saved in a recognizable place in any code we generate. However
// only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved ebp
// is really a frame pointer.
intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset);
bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
if (!saved_fp_safe) {
return false;
}
// construct the potential sender
frame sender(sender_sp, saved_fp, sender_pc);
return sender.is_interpreted_frame_valid(thread);
}
// We must always be able to find a recognizable pc
CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
if (sender_pc == NULL || sender_blob == NULL) {
return false;
}
// Could be a zombie method
if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
return false;
}
// Could just be some random pointer within the codeBlob
if (!sender_blob->code_contains(sender_pc)) {
return false;
}
// We should never be able to see an adapter if the current frame is something from code cache
if (sender_blob->is_adapter_blob()) {
return false;
}
// Could be the call_stub
if (StubRoutines::returns_to_call_stub(sender_pc)) {
intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset);
bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
if (!saved_fp_safe) {
return false;
}
// construct the potential sender
frame sender(sender_sp, saved_fp, sender_pc);
// Validate the JavaCallWrapper an entry frame must have
address jcw = (address)sender.entry_frame_call_wrapper();
bool jcw_safe = (jcw < thread->stack_base()) && ( jcw > (address)sender.fp());
return jcw_safe;
}
if (sender_blob->is_nmethod()) {
nmethod* nm = sender_blob->as_nmethod_or_null();
if (nm != NULL) {
if (nm->is_deopt_mh_entry(sender_pc) || nm->is_deopt_entry(sender_pc)) {
return false;
}
}
}
// If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
// because the return address counts against the callee's frame.
if (sender_blob->frame_size() <= 0) {
assert(!sender_blob->is_nmethod(), "should count return address at least");
return false;
}
// We should never be able to see anything here except an nmethod. If something in the
// code cache (current frame) is called by an entity within the code cache that entity
// should not be anything but the call stub (already covered), the interpreter (already covered)
// or an nmethod.
if (!sender_blob->is_nmethod()) {
return false;
}
// Could put some more validation for the potential non-interpreted sender
// frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
// One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
// We've validated the potential sender that would be created
return true;
}
// Must be native-compiled frame. Since sender will try and use fp to find
// linkages it must be safe
if (!fp_safe) {
return false;
}
// Will the pc we fetch be non-zero (which we'll find at the oldest frame)
if ( (address) this->fp()[return_addr_offset] == NULL) return false;
// could try and do some more potential verification of native frame if we could think of some...
return true;
}
void frame::patch_pc(Thread* thread, address pc) {
address* pc_addr = &(((address*) sp())[-1]);
if (TracePcPatching) {
tty->print_cr("patch_pc at address " INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "]",
pc_addr, *pc_addr, pc);
}
// Either the return address is the original one or we are going to
// patch in the same address that's already there.
assert(_pc == *pc_addr || pc == *pc_addr, "must be");
*pc_addr = pc;
_cb = CodeCache::find_blob(pc);
address original_pc = nmethod::get_deopt_original_pc(this);
if (original_pc != NULL) {
assert(original_pc == _pc, "expected original PC to be stored before patching");
_deopt_state = is_deoptimized;
// leave _pc as is
} else {
_deopt_state = not_deoptimized;
_pc = pc;
}
}
bool frame::is_interpreted_frame() const {
return Interpreter::contains(pc());
}
int frame::frame_size(RegisterMap* map) const {
frame sender = this->sender(map);
return sender.sp() - sp();
}
intptr_t* frame::entry_frame_argument_at(int offset) const {
// convert offset to index to deal with tsi
int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
// Entry frame's arguments are always in relation to unextended_sp()
return &unextended_sp()[index];
}
// sender_sp
#ifdef CC_INTERP
intptr_t* frame::interpreter_frame_sender_sp() const {
assert(is_interpreted_frame(), "interpreted frame expected");
// QQQ why does this specialize method exist if frame::sender_sp() does same thing?
// seems odd and if we always know interpreted vs. non then sender_sp() is really
// doing too much work.
return get_interpreterState()->sender_sp();
}
// monitor elements
BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
return get_interpreterState()->monitor_base();
}
BasicObjectLock* frame::interpreter_frame_monitor_end() const {
return (BasicObjectLock*) get_interpreterState()->stack_base();
}
#else // CC_INTERP
intptr_t* frame::interpreter_frame_sender_sp() const {
assert(is_interpreted_frame(), "interpreted frame expected");
return (intptr_t*) at(interpreter_frame_sender_sp_offset);
}
void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
assert(is_interpreted_frame(), "interpreted frame expected");
ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
}
// monitor elements
BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
}
BasicObjectLock* frame::interpreter_frame_monitor_end() const {
BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
// make sure the pointer points inside the frame
assert(sp() <= (intptr_t*) result, "monitor end should be above the stack pointer");
assert((intptr_t*) result < fp(), "monitor end should be strictly below the frame pointer");
return result;
}
void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
*((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
}
// Used by template based interpreter deoptimization
void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
*((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
}
#endif // CC_INTERP
frame frame::sender_for_entry_frame(RegisterMap* map) const {
assert(map != NULL, "map must be set");
// Java frame called from C; skip all C frames and return top C
// frame of that chunk as the sender
JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
assert(!entry_frame_is_first(), "next Java fp must be non zero");
assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
map->clear();
assert(map->include_argument_oops(), "should be set by clear");
if (jfa->last_Java_pc() != NULL ) {
frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
return fr;
}
frame fr(jfa->last_Java_sp(), jfa->last_Java_fp());
return fr;
}
//------------------------------------------------------------------------------
// frame::verify_deopt_original_pc
//
// Verifies the calculated original PC of a deoptimization PC for the
// given unextended SP. The unextended SP might also be the saved SP
// for MethodHandle call sites.
#ifdef ASSERT
void frame::verify_deopt_original_pc(nmethod* nm, intptr_t* unextended_sp, bool is_method_handle_return) {
frame fr;
// This is ugly but it's better than to change {get,set}_original_pc
// to take an SP value as argument. And it's only a debugging
// method anyway.
fr._unextended_sp = unextended_sp;
address original_pc = nm->get_original_pc(&fr);
assert(nm->insts_contains(original_pc), "original PC must be in nmethod");
assert(nm->is_method_handle_return(original_pc) == is_method_handle_return, "must be");
}
#endif
//------------------------------------------------------------------------------
// frame::adjust_unextended_sp
void frame::adjust_unextended_sp() {
// If we are returning to a compiled MethodHandle call site, the
// saved_fp will in fact be a saved value of the unextended SP. The
// simplest way to tell whether we are returning to such a call site
// is as follows:
nmethod* sender_nm = (_cb == NULL) ? NULL : _cb->as_nmethod_or_null();
if (sender_nm != NULL) {
// If the sender PC is a deoptimization point, get the original
// PC. For MethodHandle call site the unextended_sp is stored in
// saved_fp.
if (sender_nm->is_deopt_mh_entry(_pc)) {
DEBUG_ONLY(verify_deopt_mh_original_pc(sender_nm, _fp));
_unextended_sp = _fp;
}
else if (sender_nm->is_deopt_entry(_pc)) {
DEBUG_ONLY(verify_deopt_original_pc(sender_nm, _unextended_sp));
}
else if (sender_nm->is_method_handle_return(_pc)) {
_unextended_sp = _fp;
}
}
}
//------------------------------------------------------------------------------
// frame::update_map_with_saved_link
void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
// The interpreter and compiler(s) always save EBP/RBP in a known
// location on entry. We must record where that location is
// so this if EBP/RBP was live on callout from c2 we can find
// the saved copy no matter what it called.
// Since the interpreter always saves EBP/RBP if we record where it is then
// we don't have to always save EBP/RBP on entry and exit to c2 compiled
// code, on entry will be enough.
map->set_location(rbp->as_VMReg(), (address) link_addr);
#ifdef AMD64
// this is weird "H" ought to be at a higher address however the
// oopMaps seems to have the "H" regs at the same address and the
// vanilla register.
// XXXX make this go away
if (true) {
map->set_location(rbp->as_VMReg()->next(), (address) link_addr);
}
#endif // AMD64
}
//------------------------------------------------------------------------------
// frame::sender_for_interpreter_frame
frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
// SP is the raw SP from the sender after adapter or interpreter
// extension.
intptr_t* sender_sp = this->sender_sp();
// This is the sp before any possible extension (adapter/locals).
intptr_t* unextended_sp = interpreter_frame_sender_sp();
#ifdef COMPILER2
if (map->update_map()) {
update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
}
#endif // COMPILER2
return frame(sender_sp, unextended_sp, link(), sender_pc());
}
//------------------------------------------------------------------------------
// frame::sender_for_compiled_frame
frame frame::sender_for_compiled_frame(RegisterMap* map) const {
assert(map != NULL, "map must be set");
// frame owned by optimizing compiler
assert(_cb->frame_size() >= 0, "must have non-zero frame size");
intptr_t* sender_sp = unextended_sp() + _cb->frame_size();
intptr_t* unextended_sp = sender_sp;
// On Intel the return_address is always the word on the stack
address sender_pc = (address) *(sender_sp-1);
// This is the saved value of EBP which may or may not really be an FP.
// It is only an FP if the sender is an interpreter frame (or C1?).
intptr_t** saved_fp_addr = (intptr_t**) (sender_sp - frame::sender_sp_offset);
if (map->update_map()) {
// Tell GC to use argument oopmaps for some runtime stubs that need it.
// For C1, the runtime stub might not have oop maps, so set this flag
// outside of update_register_map.
map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
if (_cb->oop_maps() != NULL) {
OopMapSet::update_register_map(this, map);
}
// Since the prolog does the save and restore of EBP there is no oopmap
// for it so we must fill in its location as if there was an oopmap entry
// since if our caller was compiled code there could be live jvm state in it.
update_map_with_saved_link(map, saved_fp_addr);
}
assert(sender_sp != sp(), "must have changed");
return frame(sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
}
//------------------------------------------------------------------------------
// frame::sender
frame frame::sender(RegisterMap* map) const {
// Default is we done have to follow them. The sender_for_xxx will
// update it accordingly
map->set_include_argument_oops(false);
if (is_entry_frame()) return sender_for_entry_frame(map);
if (is_interpreted_frame()) return sender_for_interpreter_frame(map);
assert(_cb == CodeCache::find_blob(pc()),"Must be the same");
if (_cb != NULL) {
return sender_for_compiled_frame(map);
}
// Must be native-compiled frame, i.e. the marshaling code for native
// methods that exists in the core system.
return frame(sender_sp(), link(), sender_pc());
}
bool frame::interpreter_frame_equals_unpacked_fp(intptr_t* fp) {
assert(is_interpreted_frame(), "must be interpreter frame");
Method* method = interpreter_frame_method();
// When unpacking an optimized frame the frame pointer is
// adjusted with:
int diff = (method->max_locals() - method->size_of_parameters()) *
Interpreter::stackElementWords;
return _fp == (fp - diff);
}
void frame::pd_gc_epilog() {
// nothing done here now
}
bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
// QQQ
#ifdef CC_INTERP
#else
assert(is_interpreted_frame(), "Not an interpreted frame");
// These are reasonable sanity checks
if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
return false;
}
if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
return false;
}
if (fp() + interpreter_frame_initial_sp_offset < sp()) {
return false;
}
// These are hacks to keep us out of trouble.
// The problem with these is that they mask other problems
if (fp() <= sp()) { // this attempts to deal with unsigned comparison above
return false;
}
// do some validation of frame elements
// first the method
Method* m = *interpreter_frame_method_addr();
// validate the method we'd find in this potential sender
if (!m->is_valid_method()) return false;
// stack frames shouldn't be much larger than max_stack elements
if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
return false;
}
// validate bci/bcx
intptr_t bcx = interpreter_frame_bcx();
if (m->validate_bci_from_bcx(bcx) < 0) {
return false;
}
// validate ConstantPoolCache*
ConstantPoolCache* cp = *interpreter_frame_cache_addr();
if (cp == NULL || !cp->is_metaspace_object()) return false;
// validate locals
address locals = (address) *interpreter_frame_locals_addr();
if (locals > thread->stack_base() || locals < (address) fp()) return false;
// We'd have to be pretty unlucky to be mislead at this point
#endif // CC_INTERP
return true;
}
BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
#ifdef CC_INTERP
// Needed for JVMTI. The result should always be in the
// interpreterState object
interpreterState istate = get_interpreterState();
#endif // CC_INTERP
assert(is_interpreted_frame(), "interpreted frame expected");
Method* method = interpreter_frame_method();
BasicType type = method->result_type();
intptr_t* tos_addr;
if (method->is_native()) {
// Prior to calling into the runtime to report the method_exit the possible
// return value is pushed to the native stack. If the result is a jfloat/jdouble
// then ST0 is saved before EAX/EDX. See the note in generate_native_result
tos_addr = (intptr_t*)sp();
if (type == T_FLOAT || type == T_DOUBLE) {
// QQQ seems like this code is equivalent on the two platforms
#ifdef AMD64
// This is times two because we do a push(ltos) after pushing XMM0
// and that takes two interpreter stack slots.
tos_addr += 2 * Interpreter::stackElementWords;
#else
tos_addr += 2;
#endif // AMD64
}
} else {
tos_addr = (intptr_t*)interpreter_frame_tos_address();
}
switch (type) {
case T_OBJECT :
case T_ARRAY : {
oop obj;
if (method->is_native()) {
#ifdef CC_INTERP
obj = istate->_oop_temp;
#else
obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
#endif // CC_INTERP
} else {
oop* obj_p = (oop*)tos_addr;
obj = (obj_p == NULL) ? (oop)NULL : *obj_p;
}
assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
*oop_result = obj;
break;
}
case T_BOOLEAN : value_result->z = *(jboolean*)tos_addr; break;
case T_BYTE : value_result->b = *(jbyte*)tos_addr; break;
case T_CHAR : value_result->c = *(jchar*)tos_addr; break;
case T_SHORT : value_result->s = *(jshort*)tos_addr; break;
case T_INT : value_result->i = *(jint*)tos_addr; break;
case T_LONG : value_result->j = *(jlong*)tos_addr; break;
case T_FLOAT : {
#ifdef AMD64
value_result->f = *(jfloat*)tos_addr;
#else
if (method->is_native()) {
jdouble d = *(jdouble*)tos_addr; // Result was in ST0 so need to convert to jfloat
value_result->f = (jfloat)d;
} else {
value_result->f = *(jfloat*)tos_addr;
}
#endif // AMD64
break;
}
case T_DOUBLE : value_result->d = *(jdouble*)tos_addr; break;
case T_VOID : /* Nothing to do */ break;
default : ShouldNotReachHere();
}
return type;
}
intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
return &interpreter_frame_tos_address()[index];
}
#ifndef PRODUCT
#define DESCRIBE_FP_OFFSET(name) \
values.describe(frame_no, fp() + frame::name##_offset, #name)
void frame::describe_pd(FrameValues& values, int frame_no) {
if (is_interpreted_frame()) {
DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
DESCRIBE_FP_OFFSET(interpreter_frame_method);
DESCRIBE_FP_OFFSET(interpreter_frame_mdx);
DESCRIBE_FP_OFFSET(interpreter_frame_cache);
DESCRIBE_FP_OFFSET(interpreter_frame_locals);
DESCRIBE_FP_OFFSET(interpreter_frame_bcx);
DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
}
}
#endif
intptr_t *frame::initial_deoptimization_info() {
// used to reset the saved FP
return fp();
}
intptr_t* frame::real_fp() const {
if (_cb != NULL) {
// use the frame size if valid
int size = _cb->frame_size();
if (size > 0) {
return unextended_sp() + size;
}
}
// else rely on fp()
assert(! is_compiled_frame(), "unknown compiled frame size");
return fp();
}
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