ART: Change lock dumping
Return dex registers as well as dex PCs from FindLocksAtDexPc.
It is necessary to return the registers as the register used for
a monitor-enter operation may be aliased and overwritten by the
time the requested dex PC is reached.
It is at this point necessary to return a set of registers as
optimizations may have eliminated dead registers, and the verifier
has no notion of liveness.
A client of FindLocksAtDexPc should not assume that all registers
can be successfully retrieved from a stack frame, with the possibility
of none. Only a properly verified method (i.e., lock verification succeeded)
implies that at least one register should work for all locks held at
any point in the program.
Bug: 68703210
Test: art/test/testrunner/testrunner.py -b --host -t 167
Change-Id: I9027787e395cf8df0e7699a606665edb2ecb5136
diff --git a/runtime/verifier/method_verifier.h b/runtime/verifier/method_verifier.h
index 813ce87..c885914 100644
--- a/runtime/verifier/method_verifier.h
+++ b/runtime/verifier/method_verifier.h
@@ -149,10 +149,21 @@
void Dump(std::ostream& os) REQUIRES_SHARED(Locks::mutator_lock_);
void Dump(VariableIndentationOutputStream* vios) REQUIRES_SHARED(Locks::mutator_lock_);
+ // Information structure for a lock held at a certain point in time.
+ struct DexLockInfo {
+ // The registers aliasing the lock.
+ std::set<uint32_t> dex_registers;
+ // The dex PC of the monitor-enter instruction.
+ uint32_t dex_pc;
+
+ explicit DexLockInfo(uint32_t dex_pc_in) {
+ dex_pc = dex_pc_in;
+ }
+ };
// Fills 'monitor_enter_dex_pcs' with the dex pcs of the monitor-enter instructions corresponding
// to the locks held at 'dex_pc' in method 'm'.
static void FindLocksAtDexPc(ArtMethod* m, uint32_t dex_pc,
- std::vector<uint32_t>* monitor_enter_dex_pcs)
+ std::vector<DexLockInfo>* monitor_enter_dex_pcs)
REQUIRES_SHARED(Locks::mutator_lock_);
// Returns the accessed field corresponding to the quick instruction's field
@@ -750,7 +761,7 @@
uint32_t interesting_dex_pc_;
// The container into which FindLocksAtDexPc should write the registers containing held locks,
// null if we're not doing FindLocksAtDexPc.
- std::vector<uint32_t>* monitor_enter_dex_pcs_;
+ std::vector<DexLockInfo>* monitor_enter_dex_pcs_;
// The types of any error that occurs.
std::vector<VerifyError> failures_;