MemoryHeapBase: Save and binderize the offset

The offset that is used in the creation of the MemoryHeapBase must be saved, so
that it can be used to recreate the Heap when an IMemory object is passed
across process boundary through the binder.

Change-Id: Ie618fb5c0718e6711f55ed9235616fd801e648dc
Signed-off-by: Anu Sundararajan <sanuradha@ti.com>
Signed-off-by: Iliyan Malchev <malchev@google.com>

2 files changed, 42 insertions, 26 deletions

diff --git a/libs/binder/IMemory.cpp b/libs/binder/IMemory.cpp
index bc8c412..1ace8f8 100644
--- a/libs/binder/IMemory.cpp
+++ b/libs/binder/IMemory.cpp
@@ -42,11 +42,11 @@ class HeapCache : public IBinder::DeathRecipient
 public:
     HeapCache();
     virtual ~HeapCache();
-    
+
     virtual void binderDied(const wp<IBinder>& who);
 
-    sp<IMemoryHeap> find_heap(const sp<IBinder>& binder); 
-    void free_heap(const sp<IBinder>& binder); 
+    sp<IMemoryHeap> find_heap(const sp<IBinder>& binder);
+    void free_heap(const sp<IBinder>& binder);
     sp<IMemoryHeap> get_heap(const sp<IBinder>& binder);
     void dump_heaps();
 
@@ -57,7 +57,7 @@ private:
         int32_t         count;
     };
 
-    void free_heap(const wp<IBinder>& binder); 
+    void free_heap(const wp<IBinder>& binder);
 
     Mutex mHeapCacheLock;
     KeyedVector< wp<IBinder>, heap_info_t > mHeapCache;
@@ -81,11 +81,12 @@ public:
     virtual void* getBase() const;
     virtual size_t getSize() const;
     virtual uint32_t getFlags() const;
+    virtual uint32_t getOffset() const;
 
 private:
     friend class IMemory;
     friend class HeapCache;
-    
+
     // for debugging in this module
     static inline sp<IMemoryHeap> find_heap(const sp<IBinder>& binder) {
         return gHeapCache->find_heap(binder);
@@ -97,7 +98,7 @@ private:
         return gHeapCache->get_heap(binder);
     }
     static inline void dump_heaps() {
-        gHeapCache->dump_heaps();       
+        gHeapCache->dump_heaps();
     }
 
     void assertMapped() const;
@@ -107,6 +108,7 @@ private:
     mutable void*       mBase;
     mutable size_t      mSize;
     mutable uint32_t    mFlags;
+    mutable uint32_t    mOffset;
     mutable bool        mRealHeap;
     mutable Mutex       mLock;
 };
@@ -123,7 +125,7 @@ public:
     BpMemory(const sp<IBinder>& impl);
     virtual ~BpMemory();
     virtual sp<IMemoryHeap> getMemory(ssize_t* offset=0, size_t* size=0) const;
-    
+
 private:
     mutable sp<IMemoryHeap> mHeap;
     mutable ssize_t mOffset;
@@ -203,7 +205,7 @@ IMPLEMENT_META_INTERFACE(Memory, "android.utils.IMemory");
 BnMemory::BnMemory() {
 }
 
-BnMemory::~BnMemory() { 
+BnMemory::~BnMemory() {
 }
 
 status_t BnMemory::onTransact(
@@ -229,7 +231,7 @@ status_t BnMemory::onTransact(
 
 BpMemoryHeap::BpMemoryHeap(const sp<IBinder>& impl)
     : BpInterface<IMemoryHeap>(impl),
-        mHeapId(-1), mBase(MAP_FAILED), mSize(0), mFlags(0), mRealHeap(false)
+        mHeapId(-1), mBase(MAP_FAILED), mSize(0), mFlags(0), mOffset(0), mRealHeap(false)
 {
 }
 
@@ -242,7 +244,7 @@ BpMemoryHeap::~BpMemoryHeap() {
                 sp<IBinder> binder = const_cast<BpMemoryHeap*>(this)->asBinder();
 
                 if (VERBOSE) {
-                    LOGD("UNMAPPING binder=%p, heap=%p, size=%d, fd=%d", 
+                    LOGD("UNMAPPING binder=%p, heap=%p, size=%d, fd=%d",
                             binder.get(), this, mSize, mHeapId);
                     CallStack stack;
                     stack.update();
@@ -270,6 +272,7 @@ void BpMemoryHeap::assertMapped() const
             if (mHeapId == -1) {
                 mBase   = heap->mBase;
                 mSize   = heap->mSize;
+                mOffset = heap->mOffset;
                 android_atomic_write( dup( heap->mHeapId ), &mHeapId );
             }
         } else {
@@ -286,13 +289,14 @@ void BpMemoryHeap::assertReallyMapped() const
         // remote call without mLock held, worse case scenario, we end up
         // calling transact() from multiple threads, but that's not a problem,
         // only mmap below must be in the critical section.
-        
+
         Parcel data, reply;
         data.writeInterfaceToken(IMemoryHeap::getInterfaceDescriptor());
         status_t err = remote()->transact(HEAP_ID, data, &reply);
         int parcel_fd = reply.readFileDescriptor();
         ssize_t size = reply.readInt32();
         uint32_t flags = reply.readInt32();
+        uint32_t offset = reply.readInt32();
 
         LOGE_IF(err, "binder=%p transaction failed fd=%d, size=%ld, err=%d (%s)",
                 asBinder().get(), parcel_fd, size, err, strerror(-err));
@@ -309,7 +313,7 @@ void BpMemoryHeap::assertReallyMapped() const
         Mutex::Autolock _l(mLock);
         if (mHeapId == -1) {
             mRealHeap = true;
-            mBase = mmap(0, size, access, MAP_SHARED, fd, 0);
+            mBase = mmap(0, size, access, MAP_SHARED, fd, offset);
             if (mBase == MAP_FAILED) {
                 LOGE("cannot map BpMemoryHeap (binder=%p), size=%ld, fd=%d (%s)",
                         asBinder().get(), size, fd, strerror(errno));
@@ -317,6 +321,7 @@ void BpMemoryHeap::assertReallyMapped() const
             } else {
                 mSize = size;
                 mFlags = flags;
+                mOffset = offset;
                 android_atomic_write(fd, &mHeapId);
             }
         }
@@ -343,14 +348,19 @@ uint32_t BpMemoryHeap::getFlags() const {
     return mFlags;
 }
 
+uint32_t BpMemoryHeap::getOffset() const {
+    assertMapped();
+    return mOffset;
+}
+
 // ---------------------------------------------------------------------------
 
 IMPLEMENT_META_INTERFACE(MemoryHeap, "android.utils.IMemoryHeap");
 
-BnMemoryHeap::BnMemoryHeap() { 
+BnMemoryHeap::BnMemoryHeap() {
 }
 
-BnMemoryHeap::~BnMemoryHeap() { 
+BnMemoryHeap::~BnMemoryHeap() {
 }
 
 status_t BnMemoryHeap::onTransact(
@@ -362,6 +372,7 @@ status_t BnMemoryHeap::onTransact(
             reply->writeFileDescriptor(getHeapID());
             reply->writeInt32(getSize());
             reply->writeInt32(getFlags());
+            reply->writeInt32(getOffset());
             return NO_ERROR;
         } break;
         default:
@@ -383,17 +394,17 @@ HeapCache::~HeapCache()
 void HeapCache::binderDied(const wp<IBinder>& binder)
 {
     //LOGD("binderDied binder=%p", binder.unsafe_get());
-    free_heap(binder); 
+    free_heap(binder);
 }
 
-sp<IMemoryHeap> HeapCache::find_heap(const sp<IBinder>& binder) 
+sp<IMemoryHeap> HeapCache::find_heap(const sp<IBinder>& binder)
 {
     Mutex::Autolock _l(mHeapCacheLock);
     ssize_t i = mHeapCache.indexOfKey(binder);
     if (i>=0) {
         heap_info_t& info = mHeapCache.editValueAt(i);
         LOGD_IF(VERBOSE,
-                "found binder=%p, heap=%p, size=%d, fd=%d, count=%d", 
+                "found binder=%p, heap=%p, size=%d, fd=%d, count=%d",
                 binder.get(), info.heap.get(),
                 static_cast<BpMemoryHeap*>(info.heap.get())->mSize,
                 static_cast<BpMemoryHeap*>(info.heap.get())->mHeapId,
@@ -415,7 +426,7 @@ void HeapCache::free_heap(const sp<IBinder>& binder)  {
     free_heap( wp<IBinder>(binder) );
 }
 
-void HeapCache::free_heap(const wp<IBinder>& binder) 
+void HeapCache::free_heap(const wp<IBinder>& binder)
 {
     sp<IMemoryHeap> rel;
     {
@@ -426,7 +437,7 @@ void HeapCache::free_heap(const wp<IBinder>& binder)
             int32_t c = android_atomic_dec(&info.count);
             if (c == 1) {
                 LOGD_IF(VERBOSE,
-                        "removing binder=%p, heap=%p, size=%d, fd=%d, count=%d", 
+                        "removing binder=%p, heap=%p, size=%d, fd=%d, count=%d",
                         binder.unsafe_get(), info.heap.get(),
                         static_cast<BpMemoryHeap*>(info.heap.get())->mSize,
                         static_cast<BpMemoryHeap*>(info.heap.get())->mHeapId,
@@ -450,7 +461,7 @@ sp<IMemoryHeap> HeapCache::get_heap(const sp<IBinder>& binder)
     return realHeap;
 }
 
-void HeapCache::dump_heaps() 
+void HeapCache::dump_heaps()
 {
     Mutex::Autolock _l(mHeapCacheLock);
     int c = mHeapCache.size();
@@ -459,7 +470,7 @@ void HeapCache::dump_heaps()
         BpMemoryHeap const* h(static_cast<BpMemoryHeap const *>(info.heap.get()));
         LOGD("hey=%p, heap=%p, count=%d, (fd=%d, base=%p, size=%d)",
                 mHeapCache.keyAt(i).unsafe_get(),
-                info.heap.get(), info.count, 
+                info.heap.get(), info.count,
                 h->mHeapId, h->mBase, h->mSize);
     }
 }
diff --git a/libs/binder/MemoryHeapBase.cpp b/libs/binder/MemoryHeapBase.cpp
index 9f501e2..bf4a73f 100644
--- a/libs/binder/MemoryHeapBase.cpp
+++ b/libs/binder/MemoryHeapBase.cpp
@@ -40,15 +40,15 @@ namespace android {
 
 // ---------------------------------------------------------------------------
 
-MemoryHeapBase::MemoryHeapBase() 
+MemoryHeapBase::MemoryHeapBase()
     : mFD(-1), mSize(0), mBase(MAP_FAILED),
-      mDevice(NULL), mNeedUnmap(false) 
+      mDevice(NULL), mNeedUnmap(false), mOffset(0)
 {
 }
 
 MemoryHeapBase::MemoryHeapBase(size_t size, uint32_t flags, char const * name)
     : mFD(-1), mSize(0), mBase(MAP_FAILED), mFlags(flags),
-      mDevice(0), mNeedUnmap(false)
+      mDevice(0), mNeedUnmap(false), mOffset(0)
 {
     const size_t pagesize = getpagesize();
     size = ((size + pagesize-1) & ~(pagesize-1));
@@ -65,7 +65,7 @@ MemoryHeapBase::MemoryHeapBase(size_t size, uint32_t flags, char const * name)
 
 MemoryHeapBase::MemoryHeapBase(const char* device, size_t size, uint32_t flags)
     : mFD(-1), mSize(0), mBase(MAP_FAILED), mFlags(flags),
-      mDevice(0), mNeedUnmap(false)
+      mDevice(0), mNeedUnmap(false), mOffset(0)
 {
     int open_flags = O_RDWR;
     if (flags & NO_CACHING)
@@ -84,7 +84,7 @@ MemoryHeapBase::MemoryHeapBase(const char* device, size_t size, uint32_t flags)
 
 MemoryHeapBase::MemoryHeapBase(int fd, size_t size, uint32_t flags, uint32_t offset)
     : mFD(-1), mSize(0), mBase(MAP_FAILED), mFlags(flags),
-      mDevice(0), mNeedUnmap(false)
+      mDevice(0), mNeedUnmap(false), mOffset(0)
 {
     const size_t pagesize = getpagesize();
     size = ((size + pagesize-1) & ~(pagesize-1));
@@ -141,6 +141,7 @@ status_t MemoryHeapBase::mapfd(int fd, size_t size, uint32_t offset)
     }
     mFD = fd;
     mSize = size;
+    mOffset = offset;
     return NO_ERROR;
 }
 
@@ -183,5 +184,9 @@ const char* MemoryHeapBase::getDevice() const {
     return mDevice;
 }
 
+uint32_t MemoryHeapBase::getOffset() const {
+    return mOffset;
+}
+
 // ---------------------------------------------------------------------------
 }; // namespace android