MFC r259043:

Build an allocator for the aligned memory on top of the rtld-private
malloc.

1 files changed, 30 insertions, 0 deletions

diff --git a/libexec/rtld-elf/xmalloc.c b/libexec/rtld-elf/xmalloc.c
index 178f49b..3b3408c 100644
--- a/libexec/rtld-elf/xmalloc.c
+++ b/libexec/rtld-elf/xmalloc.c
@@ -67,3 +67,33 @@ xstrdup(const char *str)
 	memcpy(copy, str, len);
 	return (copy);
 }
+
+void *
+malloc_aligned(size_t size, size_t align)
+{
+	void *mem, *res;
+	uintptr_t x;
+	size_t asize, r;
+
+	r = round(sizeof(void *), align);
+	asize = round(size, align) + r;
+	mem = xmalloc(asize);
+	x = (uintptr_t)mem;
+	res = (void *)round(x, align);
+	*(void **)((uintptr_t)res - sizeof(void *)) = mem;
+	return (res);
+}
+
+void
+free_aligned(void *ptr)
+{
+	void *mem;
+	uintptr_t x;
+
+	if (ptr == NULL)
+		return;
+	x = (uintptr_t)ptr;
+	x -= sizeof(void *);
+	mem = *(void **)x;
+	free(mem);
+}