Merge branch 'tls-a-few-more-fixes-for-async-decrypt'

Sabrina Dubroca says:

====================
tls: a few more fixes for async decrypt

The previous patchset [1] took care of "full async". This adds a few
fixes for cases where only part of the crypto operations go the async
route, found by extending my previous debug patch [2] to do N
synchronous operations followed by M asynchronous ops (with N and M
configurable).

[1] https://patchwork.kernel.org/project/netdevbpf/list/?series=823784&state=*
[2] https://lore.kernel.org/all/9d664093b1bf7f47497b2c40b3a085b45f3274a2.1694021240.git.sd@queasysnail.net/
====================

Link: https://lore.kernel.org/r/cover.1709132643.git.sd@queasysnail.netSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/tls/tls_sw.c

@@ -52,6 +52,7 @@ struct tls_decrypt_arg {
 	struct_group(inargs,
 	bool zc;
 	bool async;
+	bool async_done;
 	u8 tail;
 	);
 
@@ -274,22 +275,30 @@ static int tls_do_decryption(struct sock *sk,
 		DEBUG_NET_WARN_ON_ONCE(atomic_read(&ctx->decrypt_pending) < 1);
 		atomic_inc(&ctx->decrypt_pending);
 	} else {
+		DECLARE_CRYPTO_WAIT(wait);
+
 		aead_request_set_callback(aead_req,
 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
-					  crypto_req_done, &ctx->async_wait);
+					  crypto_req_done, &wait);
+		ret = crypto_aead_decrypt(aead_req);
+		if (ret == -EINPROGRESS || ret == -EBUSY)
+			ret = crypto_wait_req(ret, &wait);
+		return ret;
 	}
 
 	ret = crypto_aead_decrypt(aead_req);
+	if (ret == -EINPROGRESS)
+		return 0;
+
 	if (ret == -EBUSY) {
 		ret = tls_decrypt_async_wait(ctx);
-		ret = ret ?: -EINPROGRESS;
+		darg->async_done = true;
+		/* all completions have run, we're not doing async anymore */
+		darg->async = false;
+		return ret;
 	}
-	if (ret == -EINPROGRESS) {
-		if (darg->async)
-			return 0;
 
-		ret = crypto_wait_req(ret, &ctx->async_wait);
-	}
+	atomic_dec(&ctx->decrypt_pending);
 	darg->async = false;
 
 	return ret;
@@ -1588,8 +1597,11 @@ static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov,
 	/* Prepare and submit AEAD request */
 	err = tls_do_decryption(sk, sgin, sgout, dctx->iv,
 				data_len + prot->tail_size, aead_req, darg);
-	if (err)
+	if (err) {
+		if (darg->async_done)
+			goto exit_free_skb;
 		goto exit_free_pages;
+	}
 
 	darg->skb = clear_skb ?: tls_strp_msg(ctx);
 	clear_skb = NULL;
@@ -1601,6 +1613,9 @@ static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov,
 		return err;
 	}
 
+	if (unlikely(darg->async_done))
+		return 0;
+
 	if (prot->tail_size)
 		darg->tail = dctx->tail;
 
@@ -1948,6 +1963,7 @@ int tls_sw_recvmsg(struct sock *sk,
 	struct strp_msg *rxm;
 	struct tls_msg *tlm;
 	ssize_t copied = 0;
+	ssize_t peeked = 0;
 	bool async = false;
 	int target, err;
 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
@@ -2095,8 +2111,10 @@ int tls_sw_recvmsg(struct sock *sk,
 			if (err < 0)
 				goto put_on_rx_list_err;
 
-			if (is_peek)
+			if (is_peek) {
+				peeked += chunk;
 				goto put_on_rx_list;
+			}
 
 			if (partially_consumed) {
 				rxm->offset += chunk;
@@ -2135,8 +2153,8 @@ int tls_sw_recvmsg(struct sock *sk,
 
 		/* Drain records from the rx_list & copy if required */
 		if (is_peek || is_kvec)
-			err = process_rx_list(ctx, msg, &control, copied,
-					      decrypted, is_peek, NULL);
+			err = process_rx_list(ctx, msg, &control, copied + peeked,
+					      decrypted - peeked, is_peek, NULL);
 		else
 			err = process_rx_list(ctx, msg, &control, 0,
 					      async_copy_bytes, is_peek, NULL);