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8215206: VtableStubs::find_stub is not appropriately protected by VtableStubs_lock

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Reviewed-by: thartmann, pliden
This commit is contained in:
Erik Österlund 2018-12-12 14:18:16 +01:00
parent 31fbc28af5
commit b7bd4bccbf
1 changed files with 30 additions and 25 deletions
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55
src/hotspot/share/code/vtableStubs.cpp
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@ -51,6 +51,7 @@ VMReg VtableStub::_receiver_location = VMRegImpl::Bad();
void* VtableStub::operator new(size_t size, int code_size) throw() {
assert_lock_strong(VtableStubs_lock);
assert(size == sizeof(VtableStub), "mismatched size");
// compute real VtableStub size (rounded to nearest word)
const int real_size = align_up(code_size + (int)sizeof(VtableStub), wordSize);
@ -208,31 +209,35 @@ void VtableStubs::bookkeeping(MacroAssembler* masm, outputStream* out, VtableStu
address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
assert(vtable_index >= 0, "must be positive");
VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
if (s == NULL) {
if (is_vtable_stub) {
s = create_vtable_stub(vtable_index);
} else {
s = create_itable_stub(vtable_index);
}
// Creation of vtable or itable can fail if there is not enough free space in the code cache.
VtableStub* s;
{
MutexLockerEx ml(VtableStubs_lock, Mutex::_no_safepoint_check_flag);
s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
if (s == NULL) {
return NULL;
}
if (is_vtable_stub) {
s = create_vtable_stub(vtable_index);
} else {
s = create_itable_stub(vtable_index);
}
enter(is_vtable_stub, vtable_index, s);
if (PrintAdapterHandlers) {
tty->print_cr("Decoding VtableStub %s[%d]@" INTX_FORMAT,
is_vtable_stub? "vtbl": "itbl", vtable_index, p2i(VtableStub::receiver_location()));
Disassembler::decode(s->code_begin(), s->code_end());
}
// Notify JVMTI about this stub. The event will be recorded by the enclosing
// JvmtiDynamicCodeEventCollector and posted when this thread has released
// all locks.
if (JvmtiExport::should_post_dynamic_code_generated()) {
JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub",
s->code_begin(), s->code_end());
// Creation of vtable or itable can fail if there is not enough free space in the code cache.
if (s == NULL) {
return NULL;
}
enter(is_vtable_stub, vtable_index, s);
if (PrintAdapterHandlers) {
tty->print_cr("Decoding VtableStub %s[%d]@" INTX_FORMAT,
is_vtable_stub? "vtbl": "itbl", vtable_index, p2i(VtableStub::receiver_location()));
Disassembler::decode(s->code_begin(), s->code_end());
}
// Notify JVMTI about this stub. The event will be recorded by the enclosing
// JvmtiDynamicCodeEventCollector and posted when this thread has released
// all locks.
if (JvmtiExport::should_post_dynamic_code_generated()) {
JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub",
s->code_begin(), s->code_end());
}
}
}
return s->entry_point();
@ -247,7 +252,7 @@ inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){
VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) {
MutexLockerEx ml(VtableStubs_lock, Mutex::_no_safepoint_check_flag);
assert_lock_strong(VtableStubs_lock);
unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index);
VtableStub* s = _table[hash];
while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next();
@ -256,7 +261,7 @@ VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) {
void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) {
MutexLockerEx ml(VtableStubs_lock, Mutex::_no_safepoint_check_flag);
assert_lock_strong(VtableStubs_lock);
assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub");
unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index);
// enter s at the beginning of the corresponding list