Fix memory poisoning with Asan on arbitrary byte boundaries
Asan poisons memory with an 8-byte granularity. We want to make sure that
the whole specified region is poisoned (our typical use case is a
heap-allocated object, and we want to poison the whole object, and we don't
care about the bytes after the end of the object and up to the beginning of
the next object). So align the start and end of the region to (un)poison to
an 8-byte boundary.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/include/test/memory.h b/tests/include/test/memory.h
index 27baf7a..f610a97 100644
--- a/tests/include/test/memory.h
+++ b/tests/include/test/memory.h
@@ -40,6 +40,10 @@
* Poison a memory area so that any attempt to read or write from it will
* cause a runtime failure.
*
+ * Depending on the implementation, this may poison a few bytes beyond the
+ * indicated region, but will never poison a separate object on the heap
+ * or a separate object with more than the alignment of a long long.
+ *
* The behavior is undefined if any part of the memory area is invalid.
*
* This is a no-op in builds without a poisoning method.