ART: Make trampoline compiler pointer-size-safe
The trampoline compiler uses offsets of runtime structures which
may change with the pointer size.
Add offset tests to jni_internal_test.
Bug: 26071368
(cherry picked from commit da9b763abc712fd6d1e24170a194abfbe795b8cd)
Change-Id: I01d1a3727f46b3015ac677afb5427337c3093402
diff --git a/runtime/jni_env_ext.cc b/runtime/jni_env_ext.cc
index dab1040..aa25f67 100644
--- a/runtime/jni_env_ext.cc
+++ b/runtime/jni_env_ext.cc
@@ -105,9 +105,32 @@
stacked_local_ref_cookies.pop_back();
}
-Offset JNIEnvExt::SegmentStateOffset() {
- return Offset(OFFSETOF_MEMBER(JNIEnvExt, locals) +
- IndirectReferenceTable::SegmentStateOffset().Int32Value());
+// Note: the offset code is brittle, as we can't use OFFSETOF_MEMBER or offsetof easily. Thus, there
+// are tests in jni_internal_test to match the results against the actual values.
+
+// This is encoding the knowledge of the structure and layout of JNIEnv fields.
+static size_t JNIEnvSize(size_t pointer_size) {
+ // A single pointer.
+ return pointer_size;
+}
+
+Offset JNIEnvExt::SegmentStateOffset(size_t pointer_size) {
+ size_t locals_offset = JNIEnvSize(pointer_size) +
+ 2 * pointer_size + // Thread* self + JavaVMExt* vm.
+ 4 + // local_ref_cookie.
+ (pointer_size - 4); // Padding.
+ size_t irt_segment_state_offset =
+ IndirectReferenceTable::SegmentStateOffset(pointer_size).Int32Value();
+ return Offset(locals_offset + irt_segment_state_offset);
+}
+
+Offset JNIEnvExt::LocalRefCookieOffset(size_t pointer_size) {
+ return Offset(JNIEnvSize(pointer_size) +
+ 2 * pointer_size); // Thread* self + JavaVMExt* vm
+}
+
+Offset JNIEnvExt::SelfOffset(size_t pointer_size) {
+ return Offset(JNIEnvSize(pointer_size));
}
// Use some defining part of the caller's frame as the identifying mark for the JNI segment.