1 files changed, 13 insertions, 42 deletions

diff --git a/libs/binder/include/binder/Stability.h b/libs/binder/include/binder/Stability.h
index 629b565985..ce4362f763 100644
--- a/libs/binder/include/binder/Stability.h
+++ b/libs/binder/include/binder/Stability.h
@@ -44,10 +44,9 @@ namespace internal {
 //   to old servers, and new servers know how to interpret the 8-byte result,
 //   they can still communicate.
 //
-// Every binder object has a stability level associated with it, and when
-// communicating with a binder, we make sure that the command we sent is one
-// that it knows how to process. The summary of stability of a binder is
-// represented by a Stability::Category object.
+// This class is specifically about (1). (2) is not currently tracked by
+// libbinder for regular binder calls, and everything on the system uses the
+// same copy of libbinder.
 
 class Stability final {
 public:
@@ -128,7 +127,10 @@ private:
 
     static void tryMarkCompilationUnit(IBinder* binder);
 
-    enum Level : uint8_t {
+    // Currently, we use int16_t for Level so that it can fit in BBinder.
+    // However, on the wire, we have 4 bytes reserved for stability, so whenever
+    // we ingest a Level, we always accept an int32_t.
+    enum Level : int16_t {
         UNDECLARED = 0,
 
         VENDOR = 0b000011,
@@ -136,37 +138,6 @@ private:
         VINTF = 0b111111,
     };
 
-    // This is the format of stability passed on the wire. It is only 2 bytes
-    // long, but 2 bytes in addition to this are reserved here. The difference
-    // in size is in order to free up space in BBinder, which is fixed by
-    // prebuilts inheriting from it.
-    struct Category {
-        static inline Category fromRepr(int16_t representation) {
-            return *reinterpret_cast<Category*>(&representation);
-        }
-        int16_t repr() const { return *reinterpret_cast<const int16_t*>(this); }
-        static inline Category currentFromLevel(Level level);
-
-        bool operator== (const Category& o) const {
-            return repr() == o.repr();
-        }
-        bool operator!= (const Category& o) const {
-            return !(*this == o);
-        }
-
-        std::string debugString();
-
-        // This is the version of the wire protocol associated with the host
-        // process of a particular binder. As the wire protocol changes, if
-        // sending a transaction to a binder with an old version, the Parcel
-        // class must write parcels according to the version documented here.
-        uint8_t version;
-
-        // bitmask of Stability::Level
-        Level level;
-    };
-    static_assert(sizeof(Category) == sizeof(int16_t));
-
     // returns the stability according to how this was built
     static Level getLocalLevel();
 
@@ -179,18 +150,18 @@ private:
       REPR_ALLOW_DOWNGRADE = 2,
     };
     // applies stability to binder if stability level is known
-    __attribute__((warn_unused_result))
-    static status_t setRepr(IBinder* binder, int32_t representation, uint32_t flags);
+    __attribute__((warn_unused_result)) static status_t setRepr(IBinder* binder, int32_t setting,
+                                                                uint32_t flags);
 
     // get stability information as encoded on the wire
-    static Category getCategory(IBinder* binder);
+    static int16_t getRepr(IBinder* binder);
 
     // whether a transaction on binder is allowed, if the transaction
     // is done from a context with a specific stability level
-    static bool check(Category provided, Level required);
+    static bool check(int16_t provided, Level required);
 
-    static bool isDeclaredLevel(Level level);
-    static std::string levelString(Level level);
+    static bool isDeclaredLevel(int32_t level);
+    static std::string levelString(int32_t level);
 
     Stability();
 };