Fix for Hiroshi Ito discovery of mis-aligned memory allocation

git-svn-id: svn://svn.berlios.de/openocd/trunk@1205 b42882b7-edfa-0310-969c-e2dbd0fdcd60

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index 605d58aabd62c22834c1308111aea8aa978d81e0..663518a3355f82d21cf060d807149c143434c9be 100644 (file)
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -463,6 +463,39 @@ void* cmd_queue_alloc(size_t size)
        int offset;
        u8 *t;
 
+       /*
+        * WARNING:
+        *    We align/round the *SIZE* per below
+        *    so that all pointers returned by
+        *    this function are reasonably well
+        *    aligned.
+        *
+        * If we did not, then an "odd-length" request would cause the
+        * *next* allocation to be at an *odd* address, and because
+        * this function has the same type of api as malloc() - we
+        * must also return pointers that have the same type of
+        * alignment.
+        *
+        * What I do not/have is a reasonable portable means
+        * to align by... 
+        *
+        * The solution here, is based on these suggestions.
+        * http://gcc.gnu.org/ml/gcc-help/2008-12/msg00041.html
+        *
+        */
+       union worse_case_align {
+         int i;
+         long l;
+         float f;
+         void *v;
+       };
+#define ALIGN_SIZE  (sizeof(union worse_case_align))
+
+       // The alignment process.
+       size = (size + ALIGN_SIZE -1) & (~(ALIGN_SIZE-1));
+       // Done... 
+       
+
        if (*p_page)
        {
                while ((*p_page)->next)