Remove bogus extra alignment from sbrk.

Bug: https://code.google.com/p/android/issues/detail?id=37349
Change-Id: I970c7b6be7bb7fbe6bbbe2c332f05816aeb0e09f
diff --git a/libc/bionic/brk.c b/libc/bionic/brk.cpp
similarity index 84%
rename from libc/bionic/brk.c
rename to libc/bionic/brk.cpp
index bf2f108..633b914 100644
--- a/libc/bionic/brk.c
+++ b/libc/bionic/brk.cpp
@@ -25,21 +25,17 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
-#include <stddef.h>
+
 #include <unistd.h>
-#include <sys/types.h>
 
-/* shared with sbrk.c */
-char *__bionic_brk;
+/* Shared with sbrk.c. */
+extern "C" void* __bionic_brk; // TODO: should be __LIBC_HIDDEN__ but accidentally exported by NDK :-(
 
-int brk(void*  end_data)
-{
-    char*  new_brk = __brk( end_data );
-
-    if (new_brk != end_data)
-        return -1;
-
-    __bionic_brk = new_brk;
-  
+int brk(void* end_data) {
+  void* new_brk = __brk(end_data);
+  if (new_brk != end_data) {
+    return -1;
+  }
+  __bionic_brk = new_brk;
   return 0;
 }
diff --git a/libc/bionic/sbrk.c b/libc/bionic/sbrk.cpp
similarity index 72%
rename from libc/bionic/sbrk.c
rename to libc/bionic/sbrk.cpp
index a112b6c..6c9b534 100644
--- a/libc/bionic/sbrk.c
+++ b/libc/bionic/sbrk.cpp
@@ -25,36 +25,31 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #include <unistd.h>
 #include <errno.h>
 
+/* Shared with brk.c. */
+extern "C" {
+  void* __bionic_brk; // TODO: should be __LIBC_HIDDEN__ but accidentally exported by NDK :-(
+}
 
-#define  SBRK_ALIGN  32
-
-/* shared with brk() implementation */
-char*   __bionic_brk;
-
-void *sbrk(ptrdiff_t increment)
-{
-    char*  start;
-    char*  end;
-    char*  new_brk;
-  
-    if ( !__bionic_brk)
-        __bionic_brk = __brk((void*)0);
-
-    start = (char*)(((long)__bionic_brk + SBRK_ALIGN-1) & ~(SBRK_ALIGN-1));
-  end   = start + increment;
-
-  new_brk = __brk(end);
-    if (new_brk == (void*)-1)
-        return new_brk;
-    else if (new_brk < end)
-    {
-    errno = ENOMEM;
-        return (void*)-1;
+void* sbrk(ptrdiff_t increment) {
+  if (__bionic_brk == NULL) {
+    __bionic_brk = __brk(NULL);
   }
 
-    __bionic_brk = new_brk;
-  return start;
+  void* original_brk = __bionic_brk;
+  void* desired_brk = (void*) ((uintptr_t) original_brk + increment);
+
+  void* new_brk = __brk(desired_brk);
+  if (new_brk == (void*) -1) {
+    return new_brk;
+  } else if (new_brk < desired_brk) {
+    errno = ENOMEM;
+    return (void*) -1;
+  }
+
+  __bionic_brk = new_brk;
+  return original_brk;
 }