EGL: do not use sparse files for shader

- Process is killed by system with SIGBUS signal if it writes
  data to mapped sparse file on full filesystem.
- Allocate space using write() function instead of ftruncate()
  to avoid creation of sparse files on full filesystem.
  Catch write() errors to handle out-of-space case during allocation.

Bug: http://code.google.com/p/android/issues/detail?id=35376
Change-Id: Ifc366454f34e71a43a0973eda4f591a920ea3a14
Signed-off-by: Kirill Artamonov <kartamonov@nvidia.com>

1 files changed, 15 insertions, 14 deletions

diff --git a/opengl/libs/EGL/egl_cache.cpp b/opengl/libs/EGL/egl_cache.cpp
index c79fb5f285..ed2bef3d43 100644
--- a/opengl/libs/EGL/egl_cache.cpp
+++ b/opengl/libs/EGL/egl_cache.cpp
@@ -241,19 +241,11 @@ void egl_cache_t::saveBlobCacheLocked() {
         }
 
         size_t fileSize = headerSize + cacheSize;
-        if (ftruncate(fd, fileSize) == -1) {
-            ALOGE("error setting cache file size: %s (%d)", strerror(errno),
-                    errno);
-            close(fd);
-            unlink(fname);
-            return;
-        }
 
-        uint8_t* buf = reinterpret_cast<uint8_t*>(mmap(NULL, fileSize,
-                PROT_WRITE, MAP_SHARED, fd, 0));
-        if (buf == MAP_FAILED) {
-            ALOGE("error mmaping cache file: %s (%d)", strerror(errno),
-                    errno);
+        uint8_t* buf = new uint8_t [fileSize];
+        if (!buf) {
+            ALOGE("error allocating buffer for cache contents: %s (%d)",
+                    strerror(errno), errno);
             close(fd);
             unlink(fname);
             return;
@@ -264,7 +256,7 @@ void egl_cache_t::saveBlobCacheLocked() {
         if (err != OK) {
             ALOGE("error writing cache contents: %s (%d)", strerror(-err),
                     -err);
-            munmap(buf, fileSize);
+            delete [] buf;
             close(fd);
             unlink(fname);
             return;
@@ -275,7 +267,16 @@ void egl_cache_t::saveBlobCacheLocked() {
         uint32_t* crc = reinterpret_cast<uint32_t*>(buf + 4);
         *crc = crc32c(buf + headerSize, cacheSize);
 
-        munmap(buf, fileSize);
+        if (write(fd, buf, fileSize) == -1) {
+            ALOGE("error writing cache file: %s (%d)", strerror(errno),
+                    errno);
+            delete [] buf;
+            close(fd);
+            unlink(fname);
+            return;
+        }
+
+        delete [] buf;
         fchmod(fd, S_IRUSR);
         close(fd);
     }