From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64727CD13DA for ; Sun, 17 Sep 2023 20:35:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241123AbjIQUeo (ORCPT ); Sun, 17 Sep 2023 16:34:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241159AbjIQUeh (ORCPT ); Sun, 17 Sep 2023 16:34:37 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8303D101 for ; Sun, 17 Sep 2023 13:34:32 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2DA7C433C8; Sun, 17 Sep 2023 20:34:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694982872; bh=l0uu5h+IgnQds6lP0lbGaOtDE25cZhlu0BLQoB7FfLc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dVbYn+Ttc12Yf0pFyr7js7n/wZ44tPfq2IxXGEOLh9Unrin+nOmUgmqDxFuM/DCeD xqzj5h28dDd8o2lGRUvpdRSfiuMuNaDlNtEomKt04CPBy6A1CySKmke3QD4X3JYKzV Tx36hEFdXdoWQ7QAsAztDD2BBTgnfGQSnPvFxJcA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Logan Gunthorpe , renlonglong , Dave Jiang , Jon Mason Subject: [PATCH 5.15 344/511] ntb: Fix calculation ntb_transport_tx_free_entry() Date: Sun, 17 Sep 2023 21:12:51 +0200 Message-ID: <20230917191122.114891096@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191113.831992765@linuxfoundation.org> References: <20230917191113.831992765@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Jiang commit 5a7693e6bbf19b22fd6c1d2c4b7beb0a03969e2c upstream. ntb_transport_tx_free_entry() never returns 0 with the current calculation. If head == tail, then it would return qp->tx_max_entry. Change compare to tail >= head and when they are equal, a 0 would be returned. Fixes: e74bfeedad08 ("NTB: Add flow control to the ntb_netdev") Reviewed-by: Logan Gunthorpe Signed-off-by: renlonglong Signed-off-by: Dave Jiang Signed-off-by: Jon Mason Signed-off-by: Greg Kroah-Hartman --- drivers/ntb/ntb_transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -2429,7 +2429,7 @@ unsigned int ntb_transport_tx_free_entry unsigned int head = qp->tx_index; unsigned int tail = qp->remote_rx_info->entry; - return tail > head ? tail - head : qp->tx_max_entry + tail - head; + return tail >= head ? tail - head : qp->tx_max_entry + tail - head; } EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);