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-rw-r--r--payloads/libpayload/libc/malloc.c91
1 files changed, 57 insertions, 34 deletions
diff --git a/payloads/libpayload/libc/malloc.c b/payloads/libpayload/libc/malloc.c
index 8b22daa9cc..48bf32ee3b 100644
--- a/payloads/libpayload/libc/malloc.c
+++ b/payloads/libpayload/libc/malloc.c
@@ -123,7 +123,8 @@ int dma_coherent(void *ptr)
return !dma_initialized() || (dma->start <= ptr && dma->end > ptr);
}
-static void *alloc(int len, struct memory_type *type)
+/* Find free block of size >= len */
+static hdrtype_t volatile *find_free_block(int len, struct memory_type *type)
{
hdrtype_t header;
hdrtype_t volatile *ptr = (hdrtype_t volatile *)type->start;
@@ -156,37 +157,53 @@ static void *alloc(int len, struct memory_type *type)
halt();
}
- if (header & FLAG_FREE) {
- if (len <= size) {
- hdrtype_t volatile *nptr = (hdrtype_t volatile *)((uintptr_t)ptr + HDRSIZE + len);
- int nsize = size - (HDRSIZE + len);
-
- /* If there is still room in this block,
- * then mark it as such otherwise account
- * the whole space for that block.
- */
-
- if (nsize > 0) {
- /* Mark the block as used. */
- *ptr = USED_BLOCK(len);
-
- /* Create a new free block. */
- *nptr = FREE_BLOCK(nsize);
- } else {
- /* Mark the block as used. */
- *ptr = USED_BLOCK(size);
- }
-
- return (void *)((uintptr_t)ptr + HDRSIZE);
- }
- }
+ if ((header & FLAG_FREE) && len <= size)
+ return ptr;
ptr = (hdrtype_t volatile *)((uintptr_t)ptr + HDRSIZE + size);
} while (ptr < (hdrtype_t *) type->end);
/* Nothing available. */
- return (void *)NULL;
+ return NULL;
+}
+
+/* Mark the block with length 'len' as used */
+static void use_block(hdrtype_t volatile *ptr, int len)
+{
+ /* Align the size. */
+ len = ALIGN_UP(len, HDRSIZE);
+
+ hdrtype_t volatile *nptr = (hdrtype_t volatile *)
+ ((uintptr_t)ptr + HDRSIZE + len);
+ int size = SIZE(*ptr);
+ int nsize = size - (HDRSIZE + len);
+
+ /*
+ * If there is still room in this block, then mark it as such otherwise
+ * account the whole space for that block.
+ */
+ if (nsize > 0) {
+ /* Mark the block as used. */
+ *ptr = USED_BLOCK(len);
+
+ /* Create a new free block. */
+ *nptr = FREE_BLOCK(nsize);
+ } else {
+ /* Mark the block as used. */
+ *ptr = USED_BLOCK(size);
+ }
+}
+
+static void *alloc(int len, struct memory_type *type)
+{
+ hdrtype_t volatile *ptr = find_free_block(len, type);
+
+ if (ptr == NULL)
+ return NULL;
+
+ use_block(ptr, len);
+ return (void *)((uintptr_t)ptr + HDRSIZE);
}
static void _consolidate(struct memory_type *type)
@@ -277,6 +294,7 @@ void *calloc(size_t nmemb, size_t size)
void *realloc(void *ptr, size_t size)
{
void *ret, *pptr;
+ hdrtype_t volatile *block;
unsigned int osize;
struct memory_type *type = heap;
@@ -300,18 +318,23 @@ void *realloc(void *ptr, size_t size)
* reallocated the new space.
*/
free(ptr);
- ret = alloc(size, type);
+
+ block = find_free_block(size, type);
+ if (block == NULL)
+ return NULL;
+
+ ret = (void *)((uintptr_t)block + HDRSIZE);
/*
- * if ret == NULL, then doh - failure.
- * if ret == ptr then woo-hoo! no copy needed.
+ * If ret == ptr, then no copy is needed. Otherwise, move the memory to
+ * the new location, which might be before the old one and overlap since
+ * the free() above includes a _consolidate().
*/
- if (ret == NULL || ret == ptr)
- return ret;
+ if (ret != ptr)
+ memmove(ret, ptr, osize > size ? size : osize);
- /* Move the memory to the new location. Might be before the old location
- and overlap since the free() above includes a _consolidate(). */
- memmove(ret, ptr, osize > size ? size : osize);
+ /* Mark the block as used. */
+ use_block(block, size);
return ret;
}