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-rw-r--r--payloads/libpayload/libc/malloc.c13
1 files changed, 6 insertions, 7 deletions
diff --git a/payloads/libpayload/libc/malloc.c b/payloads/libpayload/libc/malloc.c
index 7756a3bc49..c03cc737fa 100644
--- a/payloads/libpayload/libc/malloc.c
+++ b/payloads/libpayload/libc/malloc.c
@@ -51,11 +51,12 @@ static void *hstart = (void *)&_heap;
static void *hend = (void *)&_eheap;
typedef unsigned int hdrtype_t;
+#define HDRSIZE (sizeof(hdrtype_t))
-#define MAGIC (0x2a << 26)
-#define FLAG_FREE (1 << 25)
-#define SIZE_BITS 25
-#define MAX_SIZE ((1 << SIZE_BITS) - 1)
+#define SIZE_BITS ((HDRSIZE << 3) - 7)
+#define MAGIC (((hdrtype_t)0x2a) << (SIZE_BITS + 1))
+#define FLAG_FREE (((hdrtype_t)0x01) << (SIZE_BITS + 0))
+#define MAX_SIZE ((((hdrtype_t)0x01) << SIZE_BITS) - 1)
#define SIZE(_h) ((_h) & MAX_SIZE)
@@ -64,8 +65,6 @@ typedef unsigned int hdrtype_t;
#define FREE_BLOCK(_s) _HEADER(_s, FLAG_FREE)
#define USED_BLOCK(_s) _HEADER(_s, 0)
-#define HDRSIZE (sizeof(hdrtype_t))
-
#define IS_FREE(_h) (((_h) & (MAGIC | FLAG_FREE)) == (MAGIC | FLAG_FREE))
#define HAS_MAGIC(_h) (((_h) & MAGIC) == MAGIC)
@@ -93,7 +92,7 @@ static void *alloc(int len)
hdrtype_t volatile *ptr = (hdrtype_t volatile *) hstart;
/* Align the size. */
- len = (len + 3) & ~3;
+ len = (len + HDRSIZE - 1) & ~(HDRSIZE - 1);
if (!len || len > MAX_SIZE)
return (void *)NULL;