Add LKL arch implementation of memmove.

arch/lkl/include/asm/string.h

@@ -38,8 +38,36 @@ static inline void *__memset(void *s, int c, size_t count)
 	return s;
 }
 
+#define __HAVE_ARCH_MEMMOVE
+static inline void *__memmove(void *dest, const void *src, size_t count)
+{
+	char *tmp;
+	const char *s;
+
+	if (lkl_ops->memmove)
+		return lkl_ops->memmove(dest, src, count);
+
+	/* from lib/string.c */
+
+	if (dest <= src) {
+		tmp = dest;
+		s = src;
+		while (count--)
+			*tmp++ = *s++;
+	} else {
+		tmp = dest;
+		tmp += count;
+		s = src;
+		s += count;
+		while (count--)
+			*--tmp = *--s;
+	}
+	return dest;
+}
+
 #define memcpy(dst, src, len) __memcpy(dst, src, len)
 #define memset(s, c, n) __memset(s, c, n)
+#define memmove(dst, src, len) __memmove(dst, src, len)
 
 #if defined(CONFIG_KASAN)
 
@@ -57,8 +85,10 @@ static inline void *__memset(void *s, int c, size_t count)
 
 #undef memcpy
 #undef memset
+#undef memmove
 extern void *memset(void *dst, int c, __kernel_size_t count);
 extern void *memcpy(void *dst, const void *src, __kernel_size_t count);
+extern void *memmove(void *dest, const void *src, size_t count);
 
 #endif /* __SANITIZE_ADDRESS__ */
 

arch/lkl/include/uapi/asm/host_ops.h

@@ -184,6 +184,7 @@ struct lkl_host_operations {
 
 	void* (*memcpy)(void *dest, const void *src, unsigned long count);
 	void* (*memset)(void *s, int c, unsigned long count);
+	void* (*memmove)(void *dest, const void *src, unsigned long count);
 
 	void* (*mmap)(void *addr, unsigned long size, enum lkl_prot prot);
 	int (*munmap)(void *addr, unsigned long size);

tools/lkl/lib/posix-host.c

@@ -569,6 +569,11 @@ static void *posix_memset(void *s, int c, unsigned long n)
 	return memset(s, c, (size_t)n);
 }
 
+static void *posix_memmove(void *dest, const void *src, unsigned long n)
+{
+	return memmove(dest, src, (size_t)n);
+}
+
 struct lkl_host_operations lkl_host_ops = {
 	.panic = panic,
 	.thread_create = thread_create,
@@ -607,6 +612,7 @@ struct lkl_host_operations lkl_host_ops = {
 	.jmp_buf_longjmp = jmp_buf_longjmp,
 	.memcpy = posix_memcpy,
 	.memset = posix_memset,
+	.memmove = posix_memmove,
 	.mmap = lkl_mmap,
 	.munmap = lkl_munmap,
 #ifdef LKL_HOST_CONFIG_MMU