From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E360A368D4D for ; Wed, 22 Jul 2026 17:30:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784741410; cv=none; b=ePkkBNO5nYxTr30l57HGU7U4fK94wPdf6AGl+ibW/eOdbfeHiukplCce3YB9y5ufsLeQGjQCppIOEBfCxawxxzmRGCR6Wfb5FJURnB5+l0OsfQzYlL6wrwxltA+hg1glD14+K+1pUYJu7lOve0Y9Ruac77vfXkbVnYK3Go9ZqgU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784741410; c=relaxed/simple; bh=sGd5fS984n6t4LX92j21yf8pUbUVdEY9P0Hp+vxP/7g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RFEtDwLKzWwnnh/dglwAMu+LKvrCzXB3+6Ds/Sl2y6DbgMNPHHs09gWSSRCBynKFijW1vFDtHVOOJvAftRAP2MCtAlD/MtgXN/slz4VfxnuPhcDCoz7MmT7tvuagNhFk37dinP7VMMWYIGJ3ZoQJ5jDQDJ+9hVI0PiPqpYSO4gs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TBcRCCrN; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TBcRCCrN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA2A91F000E9; Wed, 22 Jul 2026 17:30:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784741408; bh=dJneP7k2D+4eql1vmpmd9epcNVSZ3CM5FnZxaATESic=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TBcRCCrNEPYE46deRJydruBWWelSb8Vznqhmj8Ah8/OXgfItO9sfwGzqyoR7GFLt/ MF/QsF3biWpwHs4PFmNs32BdgDudCkNc14fbrzcVmF3py0qd3q8YbvvvKFUunCrlto Q26VeyR0/iiTgyeo5Mb11GuFp987H39CsCYIU58TbB88Wa2SjGLbk8t8v05uJNVeKe vWY0fPItL3FwGVV33Z279lfXubTrRh2Cu0VoxwYGmGoIx0pAqeM10vsVxJhcCLiVj5 YkeXF6ByXS2Uo2d9iLHDeLQS6ijZ1r9VfhRvkiMvZv4/zw5sXa105CVQJxJI+autDR CcTrEP78ByehQ== From: Sasha Levin To: stable@vger.kernel.org Cc: David Howells , Marc Dionne , linux-afs@lists.infradead.org, Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6.y 1/4] rxrpc: Don't need barrier for ->tx_bottom and ->acks_hard_ack Date: Wed, 22 Jul 2026 13:30:03 -0400 Message-ID: <20260722173006.2069029-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026072024-devalue-womanly-8b22@gregkh> References: <2026072024-devalue-womanly-8b22@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: David Howells [ Upstream commit 6396b48ac0a77165f9c2c40ab03d6c8188c89739 ] We don't need a barrier for the ->tx_bottom value (which indicates the lowest sequence still in the transmission queue) and the ->acks_hard_ack value (which tracks the DATA packets hard-ack'd by the latest ACK packet received and thus indicates which DATA packets can now be discarded) as the app thread doesn't use either value as a reference to memory to access. Rather, the app thread merely uses these as a guide to how much space is available in the transmission queue Change the code to use READ/WRITE_ONCE() instead. Also, change rxrpc_check_tx_space() to use the same value for tx_bottom throughout. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20241204074710.990092-18-dhowells@redhat.com Signed-off-by: Jakub Kicinski Stable-dep-of: e66f8f32f501 ("rxrpc: Fix socket notification race") Signed-off-by: Sasha Levin --- net/rxrpc/sendmsg.c | 8 +++++--- net/rxrpc/txbuf.c | 4 ++-- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c index 6939617afc7bcd..3dc54d6d4e316f 100644 --- a/net/rxrpc/sendmsg.c +++ b/net/rxrpc/sendmsg.c @@ -93,9 +93,11 @@ static int rxrpc_wait_to_be_connected(struct rxrpc_call *call, long *timeo) */ static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win) { + rxrpc_seq_t tx_bottom = READ_ONCE(call->tx_bottom); + if (_tx_win) - *_tx_win = call->tx_bottom; - return call->tx_prepared - call->tx_bottom < 256; + *_tx_win = tx_bottom; + return call->tx_prepared - tx_bottom < 256; } /* @@ -137,7 +139,7 @@ static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx, rtt = 2; timeout = rtt; - tx_start = smp_load_acquire(&call->acks_hard_ack); + tx_start = READ_ONCE(call->acks_hard_ack); for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); diff --git a/net/rxrpc/txbuf.c b/net/rxrpc/txbuf.c index d43be851238640..84d067fbc2fd10 100644 --- a/net/rxrpc/txbuf.c +++ b/net/rxrpc/txbuf.c @@ -112,14 +112,14 @@ void rxrpc_shrink_call_tx_buffer(struct rxrpc_call *call) while ((txb = list_first_entry_or_null(&call->tx_buffer, struct rxrpc_txbuf, call_link))) { - hard_ack = smp_load_acquire(&call->acks_hard_ack); + hard_ack = call->acks_hard_ack; if (before(hard_ack, txb->seq)) break; if (txb->seq != call->tx_bottom + 1) rxrpc_see_txbuf(txb, rxrpc_txbuf_see_out_of_step); ASSERTCMP(txb->seq, ==, call->tx_bottom + 1); - smp_store_release(&call->tx_bottom, call->tx_bottom + 1); + WRITE_ONCE(call->tx_bottom, call->tx_bottom + 1); list_del_rcu(&txb->call_link); trace_rxrpc_txqueue(call, rxrpc_txqueue_dequeue); -- 2.53.0