X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmalloc%2Fmemalign.c;h=cf9dfbda66ca295c543a16ff1202ef0a118f785b;hb=03919b26ed41c31876db41f7cee076ced4513fad;hp=61f456e48667e6a717802eadc5a471d46a8121a7;hpb=0b44a0315b47dd8eced9f3b7f31580cf14bbfc01;p=musl

diff --git a/src/malloc/memalign.c b/src/malloc/memalign.c
index 61f456e4..cf9dfbda 100644
--- a/src/malloc/memalign.c
+++ b/src/malloc/memalign.c
@@ -1,13 +1,54 @@
 #include <stdlib.h>
+#include <stdint.h>
 #include <errno.h>
+#include "malloc_impl.h"
 
-void *memalign(size_t align, size_t len)
+void *__memalign(size_t align, size_t len)
 {
-	void *mem;
-	int ret;
-	if ((ret = posix_memalign(&mem, align, len))) {
-		errno = ret;
+	unsigned char *mem, *new;
+
+	if ((align & -align) != align) {
+		errno = EINVAL;
+		return 0;
+	}
+
+	if (len > SIZE_MAX - align || __malloc_replaced) {
+		errno = ENOMEM;
 		return 0;
 	}
-	return mem;
+
+	if (align <= SIZE_ALIGN)
+		return malloc(len);
+
+	if (!(mem = malloc(len + align-1)))
+		return 0;
+
+	new = (void *)((uintptr_t)mem + align-1 & -align);
+	if (new == mem) return mem;
+
+	struct chunk *c = MEM_TO_CHUNK(mem);
+	struct chunk *n = MEM_TO_CHUNK(new);
+
+	if (IS_MMAPPED(c)) {
+		/* Apply difference between aligned and original
+		 * address to the "extra" field of mmapped chunk. */
+		n->psize = c->psize + (new-mem);
+		n->csize = c->csize - (new-mem);
+		return new;
+	}
+
+	struct chunk *t = NEXT_CHUNK(c);
+
+	/* Split the allocated chunk into two chunks. The aligned part
+	 * that will be used has the size in its footer reduced by the
+	 * difference between the aligned and original addresses, and
+	 * the resulting size copied to its header. A new header and
+	 * footer are written for the split-off part to be freed. */
+	n->psize = c->csize = C_INUSE | (new-mem);
+	n->csize = t->psize -= new-mem;
+
+	__bin_chunk(c);
+	return new;
 }
+
+weak_alias(__memalign, memalign);