New patch to review for coreboot: a185b90 libpayload: Make heap code independent of its header size

[Patrick Georgi]

Patrick Georgi ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3888

-gerrit

commit a185b90d0ada57a89a76c8f39b54fa3004ace0fb
Author: Nico Huber 
Date:   Fri Jun 14 15:26:49 2013 +0200

libpayload: Make heap code independent of its header size

Signed-off-by: Patrick Georgi 
    Change-Id: Ie69ceb343494b7dd309847b7d606cb47925f68b6
---
 payloads/libpayload/libc/malloc.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/payloads/libpayload/libc/malloc.c b/payloads/libpayload/libc/malloc.c
index 7756a3b..c03cc73 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;