RDMA/uverbs: Optimize clearing of extra bytes in response (9435ef4c) · Commits · 戴 / test

Clear extra bytes in response in batch manner instead of doing it per-byte. Signed-off-by:

drivers/infiniband/core/uverbs_cmd.c

+8 −6

Original line number	Diff line number	Diff line
		@@ -58,19 +58,21 @@
		static int uverbs_response(struct uverbs_attr_bundle attrs, const void resp,
		size_t resp_len)
		{
		u8 __user *cur = attrs->ucore.outbuf + resp_len;
		u8 __user *end = attrs->ucore.outbuf + attrs->ucore.outlen;
		int ret;

		if (copy_to_user(attrs->ucore.outbuf, resp,
		min(attrs->ucore.outlen, resp_len)))
		return -EFAULT;

		/* Zero fill any extra memory that user space might have provided */
		for (; cur < end; cur++) {
		ret = put_user(0, cur);
		if (resp_len < attrs->ucore.outlen) {
		/*
		* Zero fill any extra memory that user
		* space might have provided.
		*/
		ret = clear_user(attrs->ucore.outbuf + resp_len,
		attrs->ucore.outlen - resp_len);
		if (ret)
		return ret;
		return -EFAULT;
		}

		return 0;