1 files changed, 46 insertions, 0 deletions
diff --git a/src/malloc/lite_malloc.c b/src/malloc/lite_malloc.c
new file mode 100644
index 00000000..c8293908
--- /dev/null
+++ b/src/malloc/lite_malloc.c
@@ -0,0 +1,46 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include <errno.h>
+#include "libc.h"
+
+uintptr_t __brk(uintptr_t);
+
+#define ALIGN 16
+
+void *__simple_malloc(size_t n)
+{
+	static uintptr_t cur, brk;
+	uintptr_t base, new;
+	static int lock;
+	size_t align=1;
+
+	if (!n) n++;
+	if (n > SIZE_MAX/2) goto toobig;
+
+	while (align<n && align<ALIGN)
+		align += align;
+	n = n + align - 1 & -align;
+
+	LOCK(&lock);
+	if (!cur) cur = brk = __brk(0)+16;
+	base = cur + align-1 & -align;
+	if (n > SIZE_MAX - PAGE_SIZE - base) goto fail;
+	if (base+n > brk) {
+		new = base+n + PAGE_SIZE-1 & -PAGE_SIZE;
+		if (__brk(new) != new) goto fail;
+		brk = new;
+	}
+	cur = base+n;
+	UNLOCK(&lock);
+
+	return (void *)base;
+
+fail:
+	UNLOCK(&lock);
+toobig:
+	errno = ENOMEM;
+	return 0;
+}
+
+weak_alias(__simple_malloc, malloc);