[PATCH 5.15 1/5] tls: rx: simplify async wait

[Shaoying Xu <shaoyi@amazon.com>]

From: Jakub Kicinski <kuba@kernel.org>

commit 37943f047bfb88ba4dfc7a522563f57c86d088a0 upstream.

Since we are protected from async completions by decrypt_compl_lock
we can drop the async_notify and reinit the completion before we
start waiting.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: aec7961916f3 ("tls: fix race between async notify and socket close")
Cc: <stable@vger.kernel.org> # 5.15
Signed-off-by: Shaoying Xu <shaoyi@amazon.com>
---
 include/net/tls.h |  1 -
 net/tls/tls_sw.c  | 14 ++------------
 2 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index ea0aeae26cf7..dcd6aa08c067 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -150,7 +150,6 @@ struct tls_sw_context_rx {
 	atomic_t decrypt_pending;
 	/* protect crypto_wait with decrypt_pending*/
 	spinlock_t decrypt_compl_lock;
-	bool async_notify;
 };
 
 struct tls_record_info {
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index fc55b65695e5..9c443646417e 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -174,7 +174,6 @@ static void tls_decrypt_done(struct crypto_async_request *req, int err)
 	struct scatterlist *sg;
 	struct sk_buff *skb;
 	unsigned int pages;
-	int pending;
 
 	skb = (struct sk_buff *)req->data;
 	tls_ctx = tls_get_ctx(skb->sk);
@@ -222,9 +221,7 @@ static void tls_decrypt_done(struct crypto_async_request *req, int err)
 	kfree(aead_req);
 
 	spin_lock_bh(&ctx->decrypt_compl_lock);
-	pending = atomic_dec_return(&ctx->decrypt_pending);
-
-	if (!pending && ctx->async_notify)
+	if (!atomic_dec_return(&ctx->decrypt_pending))
 		complete(&ctx->async_wait.completion);
 	spin_unlock_bh(&ctx->decrypt_compl_lock);
 }
@@ -1917,7 +1914,7 @@ int tls_sw_recvmsg(struct sock *sk,
 
 		/* Wait for all previously submitted records to be decrypted */
 		spin_lock_bh(&ctx->decrypt_compl_lock);
-		ctx->async_notify = true;
+		reinit_completion(&ctx->async_wait.completion);
 		pending = atomic_read(&ctx->decrypt_pending);
 		spin_unlock_bh(&ctx->decrypt_compl_lock);
 		if (pending) {
@@ -1929,15 +1926,8 @@ int tls_sw_recvmsg(struct sock *sk,
 				decrypted = 0;
 				goto end;
 			}
-		} else {
-			reinit_completion(&ctx->async_wait.completion);
 		}
 
-		/* There can be no concurrent accesses, since we have no
-		 * pending decrypt operations
-		 */
-		WRITE_ONCE(ctx->async_notify, false);
-
 		/* Drain records from the rx_list & copy if required */
 		if (is_peek || is_kvec)
 			err = process_rx_list(ctx, msg, &control, copied,
-- 
2.40.1