ART: (Partially) fix lock aliasing
On monitor-exit, we must unlock all the registers which purport to
be locked at the current lock depth. These are lock aliases.
Bug: 20102779
Bug: 21169615
Bug: 21988678
Bug: 23300986
Change-Id: I6604871fc778d8f0ca9a99f6aad16a99ab62c599
diff --git a/runtime/verifier/register_line.h b/runtime/verifier/register_line.h
index f61e51f..a9c4c95 100644
--- a/runtime/verifier/register_line.h
+++ b/runtime/verifier/register_line.h
@@ -344,6 +344,14 @@
} else {
reg_to_lock_depths_.erase(it);
}
+ // Need to unlock every register at the same lock depth. These are aliased locks.
+ uint32_t mask = 1 << depth;
+ for (auto& pair : reg_to_lock_depths_) {
+ if ((pair.second & mask) != 0) {
+ VLOG(verifier) << "Also unlocking " << pair.first;
+ pair.second ^= mask;
+ }
+ }
}
void ClearAllRegToLockDepths(size_t reg) {
diff --git a/test/800-smali/expected.txt b/test/800-smali/expected.txt
index dd37cdb..21a8171 100644
--- a/test/800-smali/expected.txt
+++ b/test/800-smali/expected.txt
@@ -41,4 +41,5 @@
b/20843113
b/23201502 (float)
b/23201502 (double)
+b/23300986
Done!
diff --git a/test/800-smali/smali/b_23300986.smali b/test/800-smali/smali/b_23300986.smali
new file mode 100644
index 0000000..5ed8e5e
--- /dev/null
+++ b/test/800-smali/smali/b_23300986.smali
@@ -0,0 +1,13 @@
+.class public LB23300986;
+
+.super Ljava/lang/Object;
+
+.method public static runAliasAfterEnter(Ljava/lang/Object;)V
+ .registers 3
+ monitor-enter v2 # Lock on parameter
+ move-object v1, v2 # Copy parameter into v1, establishing an alias.
+ monitor-exit v1 # Unlock on alias
+ monitor-enter v2 # Do it again.
+ monitor-exit v1
+ return-void
+.end method
diff --git a/test/800-smali/src/Main.java b/test/800-smali/src/Main.java
index b481a1d..a89b849 100644
--- a/test/800-smali/src/Main.java
+++ b/test/800-smali/src/Main.java
@@ -127,6 +127,8 @@
new NullPointerException(), null));
testCases.add(new TestCase("b/23201502 (double)", "B23201502", "runDouble", null,
new NullPointerException(), null));
+ testCases.add(new TestCase("b/23300986", "B23300986", "runAliasAfterEnter",
+ new Object[] { new Object() }, null, null));
}
public void runTests() {
