return chunks split off by memalign using __bin_chunk instead of free

this change serves multiple purposes:

1. it ensures that static linking of memalign-family functions will
pull in the system malloc implementation, thereby causing link errors
if an attempt is made to link the system memalign functions with a
replacement malloc (incomplete allocator replacement).

2. it eliminates calls to free that are unpaired with allocations,
which are confusing when setting breakpoints or tracing execution.

as a bonus, making __bin_chunk external may discourage aggressive and
unnecessary inlining of it.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/malloc/memalign.c b/src/malloc/memalign.c
index 9c420229..7246a99b 100644
--- a/src/malloc/memalign.c
+++ b/src/malloc/memalign.c
@@ -48,7 +48,7 @@ void *__memalign(size_t align, size_t len)
 	n->psize = c->csize = C_INUSE | (new-mem);
 	n->csize = t->psize -= new-mem;
 
-	free(mem);
+	__bin_chunk(c);
 	return new;
 }