FLACExtractor: copy protect mWriteBuffer

Bug: 30895578
Bug: 34970788
Change-Id: I4cba36bbe3502678210e5925181683df9726b431
(cherry picked from commit 328cd66cc72ba7bc5452ed5a93f29ddcd73aa9f9)
(cherry picked from commit 8ee699977c155c6d67e4abd8b4259b5447148a80)

media/libstagefright/FLACExtractor.cpp

diff --git a/media/libstagefright/FLACExtractor.cpp b/media/libstagefright/FLACExtractor.cpp
index 13b66f3..543e0af 100644
--- a/media/libstagefright/FLACExtractor.cpp
+++ b/media/libstagefright/FLACExtractor.cpp
@@ -73,6 +73,10 @@
 class FLACParser : public RefBase {
 
 public:
+    enum {
+        kMaxChannels = 8,
+    };
+
     FLACParser(
         const sp<DataSource> &dataSource,
         // If metadata pointers aren't provided, we don't fill them
@@ -122,7 +126,7 @@
     // media buffers
     size_t mMaxBufferSize;
     MediaBufferGroup *mGroup;
-    void (*mCopy)(short *dst, const int *const *src, unsigned nSamples, unsigned nChannels);
+    void (*mCopy)(short *dst, const int * src[kMaxChannels], unsigned nSamples, unsigned nChannels);
 
     // handle to underlying libFLAC parser
     FLAC__StreamDecoder *mDecoder;
@@ -139,7 +143,7 @@
     bool mWriteRequested;
     bool mWriteCompleted;
     FLAC__FrameHeader mWriteHeader;
-    const FLAC__int32 * const *mWriteBuffer;
+    FLAC__int32 const * mWriteBuffer[kMaxChannels];
 
     // most recent error reported by libFLAC parser
     FLAC__StreamDecoderErrorStatus mErrorStatus;
@@ -323,7 +327,7 @@
         mWriteRequested = false;
         // FLAC parser doesn't free or realloc buffer until next frame or finish
         mWriteHeader = frame->header;
-        mWriteBuffer = buffer;
+        memmove(mWriteBuffer, buffer, sizeof(const FLAC__int32 * const) * getChannels());
         mWriteCompleted = true;
         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
     } else {
@@ -382,7 +386,7 @@
 
 static void copyMono8(
         short *dst,
-        const int *const *src,
+        const int * src[FLACParser::kMaxChannels],
         unsigned nSamples,
         unsigned /* nChannels */) {
     for (unsigned i = 0; i < nSamples; ++i) {
@@ -392,7 +396,7 @@
 
 static void copyStereo8(
         short *dst,
-        const int *const *src,
+        const int * src[FLACParser::kMaxChannels],
         unsigned nSamples,
         unsigned /* nChannels */) {
     for (unsigned i = 0; i < nSamples; ++i) {
@@ -401,7 +405,7 @@
     }
 }
 
-static void copyMultiCh8(short *dst, const int *const *src, unsigned nSamples, unsigned nChannels)
+static void copyMultiCh8(short *dst, const int * src[FLACParser::kMaxChannels], unsigned nSamples, unsigned nChannels)
 {
     for (unsigned i = 0; i < nSamples; ++i) {
         for (unsigned c = 0; c < nChannels; ++c) {
@@ -412,7 +416,7 @@
 
 static void copyMono16(
         short *dst,
-        const int *const *src,
+        const int * src[FLACParser::kMaxChannels],
         unsigned nSamples,
         unsigned /* nChannels */) {
     for (unsigned i = 0; i < nSamples; ++i) {
@@ -422,7 +426,7 @@
 
 static void copyStereo16(
         short *dst,
-        const int *const *src,
+        const int * src[FLACParser::kMaxChannels],
         unsigned nSamples,
         unsigned /* nChannels */) {
     for (unsigned i = 0; i < nSamples; ++i) {
@@ -431,7 +435,7 @@
     }
 }
 
-static void copyMultiCh16(short *dst, const int *const *src, unsigned nSamples, unsigned nChannels)
+static void copyMultiCh16(short *dst, const int * src[FLACParser::kMaxChannels], unsigned nSamples, unsigned nChannels)
 {
     for (unsigned i = 0; i < nSamples; ++i) {
         for (unsigned c = 0; c < nChannels; ++c) {
@@ -444,7 +448,7 @@
 
 static void copyMono24(
         short *dst,
-        const int *const *src,
+        const int * src[FLACParser::kMaxChannels],
         unsigned nSamples,
         unsigned /* nChannels */) {
     for (unsigned i = 0; i < nSamples; ++i) {
@@ -454,7 +458,7 @@
 
 static void copyStereo24(
         short *dst,
-        const int *const *src,
+        const int * src[FLACParser::kMaxChannels],
         unsigned nSamples,
         unsigned /* nChannels */) {
     for (unsigned i = 0; i < nSamples; ++i) {
@@ -463,7 +467,7 @@
     }
 }
 
-static void copyMultiCh24(short *dst, const int *const *src, unsigned nSamples, unsigned nChannels)
+static void copyMultiCh24(short *dst, const int * src[FLACParser::kMaxChannels], unsigned nSamples, unsigned nChannels)
 {
     for (unsigned i = 0; i < nSamples; ++i) {
         for (unsigned c = 0; c < nChannels; ++c) {
@@ -474,7 +478,7 @@
 
 static void copyTrespass(
         short * /* dst */,
-        const int *const * /* src */,
+        const int *[FLACParser::kMaxChannels] /* src */,
         unsigned /* nSamples */,
         unsigned /* nChannels */) {
     TRESPASS();
@@ -499,7 +503,6 @@
       mStreamInfoValid(false),
       mWriteRequested(false),
       mWriteCompleted(false),
-      mWriteBuffer(NULL),
       mErrorStatus((FLAC__StreamDecoderErrorStatus) -1)
 {
     ALOGV("FLACParser::FLACParser");
@@ -555,7 +558,7 @@
     }
     if (mStreamInfoValid) {
         // check channel count
-        if (getChannels() == 0 || getChannels() > 8) {
+        if (getChannels() == 0 || getChannels() > kMaxChannels) {
             ALOGE("unsupported channel count %u", getChannels());
             return NO_INIT;
         }
@@ -591,7 +594,7 @@
         static const struct {
             unsigned mChannels;
             unsigned mBitsPerSample;
-            void (*mCopy)(short *dst, const int *const *src, unsigned nSamples, unsigned nChannels);
+            void (*mCopy)(short *dst, const int * src[kMaxChannels], unsigned nSamples, unsigned nChannels);
         } table[] = {
             { 1,  8, copyMono8    },
             { 2,  8, copyStereo8  },