no longer require aligned base address

1 files changed, 7 insertions, 2 deletions

diff --git a/magic_buddy.c b/magic_buddy.c
index 52cf764..18c4e23 100644
--- a/magic_buddy.c
+++ b/magic_buddy.c
@@ -13,6 +13,7 @@ struct free_list {
 
 static struct free_list *(AVAIL[ADDRESS_BITS]);
 static size_t ROOT_LOGSIZE;
+static void *BASE;
 
 // log2 of size rounded up (ceil) or down (!ceil) to the nearest power of 2
 static size_t size2log(size_t size, int ceil) {
@@ -29,9 +30,11 @@ static size_t size2log(size_t size, int ceil) {
 
 void init_buddy(uint8_t *base, size_t size,
                 uint8_t magic[MAGIC_COOKIE_BYTES]) {
+    BASE = base;
+
     size_t logsize = size2log(size, 0);
     ROOT_LOGSIZE = logsize;
-    assert(((size_t)base & ((1 << logsize) - 1)) == 0);
+
     AVAIL[logsize] = (struct free_list *)base;
     AVAIL[logsize]->next = 0;
     AVAIL[logsize]->pprev = &(AVAIL[logsize]);
@@ -39,7 +42,9 @@ void init_buddy(uint8_t *base, size_t size,
 }
 
 static struct free_list *buddy_of(struct free_list *block, size_t logsize) {
-    return (void *)((size_t)block ^ (1 << logsize));
+    size_t virt_block = (size_t)block - (size_t)BASE;
+    size_t virt_buddy = virt_block ^ (1 << logsize);
+    return (void*)((uint8_t*)BASE + virt_buddy);
 }
 
 static int isfree(struct free_list *block) {