commit 9d8be5485c366b4f579bef0b88a4c99b899f21e1
author tedbo <tedbo@google.com> Tue Oct 05 13:06:06 2010 -0700
committer tedbo <tedbo@google.com> Tue Oct 05 13:23:28 2010 -0700
tree 9ffa7d64f6896681d17944af40ed29d3050827fd
parent abdb3695b21631ace52123fbe68f86fa4476a4b0

get_malloc_leak_info: Fix assumption that totalMemory out parameter was initialized to zero.

The get_malloc_leak_info() currently asssumes that the totalMemory out parameter
was pre-initialized to zero before the routine is called. If it is not then the
accumulated totalMemory value will be incorrect. It is likely that many callers
will simply allocate totalMemory on the stack with no initialization and assume
that get_malloc_leak_info will set the proper value.

As an example, the caller in frameworks/base/core/jni/android_os_Debug.cpp
calls get_malloc_leak_info() with the address uninitiazed stack variable
for totalMemory. It is probably best to fix this in get_malloc_leak_info.

Change-Id: I84c927c3781419585794726115b7d34d8fdd24ae

libc/bionic/malloc_debug_common.c

diff --git a/libc/bionic/malloc_debug_common.c b/libc/bionic/malloc_debug_common.c
index f05576c..ebf0006 100644
--- a/libc/bionic/malloc_debug_common.c
+++ b/libc/bionic/malloc_debug_common.c
@@ -120,6 +120,7 @@
             totalMemory == NULL || backtraceSize == NULL) {
         return;
     }
+    *totalMemory = 0;
 
     pthread_mutex_lock(&gAllocationsMutex);
 
@@ -127,7 +128,6 @@
         *info = NULL;
         *overallSize = 0;
         *infoSize = 0;
-        *totalMemory = 0;
         *backtraceSize = 0;
         goto done;
     }