From patchwork Tue May 2 21:25:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Augusto von Dentz X-Patchwork-Id: 679164 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 8D929C77B75 for ; Tue, 2 May 2023 21:25:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229891AbjEBVZi (ORCPT ); Tue, 2 May 2023 17:25:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229889AbjEBVZh (ORCPT ); Tue, 2 May 2023 17:25:37 -0400 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4613010EF for ; Tue, 2 May 2023 14:25:36 -0700 (PDT) Received: by mail-pf1-x434.google.com with SMTP id d2e1a72fcca58-64115e652eeso367782b3a.0 for ; Tue, 02 May 2023 14:25:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1683062735; x=1685654735; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=5Ka/SwIDHwEHrJuqFX1XIh48oMlHgMa3gOezG3it4Bk=; b=Zgvi5vPCxzCrmjN49/vGxfjzHtxRrYNcse/MjRqB13tFz1VNH81l4CxErXEKqxzKvX nFasVU2+FjAA383J7Ov3e4c5boylFFItnBwq004ejmBsy7427DE7wa+ukKeJROURDRgm r59FnXUi13mpmAZ1s3EM2ocvRa39YpXEkH85mU69azxvRXc/ZivnnzcA4RBCSdCWK7Zb VqGBT+SfKEC0YvgAYod1JzQq12nhLgdWpH9mCJlhHpJCpUWB3jz+++W1H6Tvm8/IPcdI Qd5ohI3FpsKAK0njXYKDinRR16x+BOI0jdvs9HcTIkbOenVE1yY+x0wxpp6WaS9kInCW 7moQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683062735; x=1685654735; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=5Ka/SwIDHwEHrJuqFX1XIh48oMlHgMa3gOezG3it4Bk=; b=A3PV3x6ssk+OB47nngZmGEw/y8DfKFdNitz8zqJcegLrd6HzzJp874DBkG8bujTp2B sBt41qSwuJHkOckZXwTrPoWZ81yRSSjARsMKP/ekXOFsF2SngU5opTpRlUi0e9gB0MNi 0kRUdY6m7XTydnzm+hK6vwJXww2uviBh94wG61mLYmrq/t5FtvqMejPkDMgiwurOzDFU I7KDn18VUQKroUldkUWLV2ZsCNCpp+AKEB5eqOVvgKg9G2zQVz7HXG8bHhbL41mRPchu x4C2HT2TrNqdNDCynR0hY/k9xSupJVMTumlsxEj8Jku8T+VwZskPATMn6gxGkMPn7WBw XSHw== X-Gm-Message-State: AC+VfDz9FR5h+EIRTupZ+88UwNCx3GfaYv6qamO4m5H9fcUeYLrg1W2F Qt1PzHcHAdXYCGG/l21c4gxIc4VgP8s= X-Google-Smtp-Source: ACHHUZ5rbCWi3v268uIKpLBOMI91xKpYfxl/TjVKmX8X+YNs3wVLaUkgNWUijTVLD2H9lEPBN/wPxg== X-Received: by 2002:aa7:8b49:0:b0:63f:32ed:92b1 with SMTP id i9-20020aa78b49000000b0063f32ed92b1mr20353403pfd.7.1683062734955; Tue, 02 May 2023 14:25:34 -0700 (PDT) Received: from lvondent-mobl4.. (c-71-59-129-171.hsd1.or.comcast.net. [71.59.129.171]) by smtp.gmail.com with ESMTPSA id j9-20020a056a00234900b0063d3d776910sm22232459pfj.138.2023.05.02.14.25.33 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 May 2023 14:25:33 -0700 (PDT) From: Luiz Augusto von Dentz To: linux-bluetooth@vger.kernel.org Subject: [PATCH v3 4/4] Bluetooth: Unlink CISes when LE disconnects in hci_conn_del Date: Tue, 2 May 2023 14:25:27 -0700 Message-Id: <20230502212527.1662896-4-luiz.dentz@gmail.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230502212527.1662896-1-luiz.dentz@gmail.com> References: <20230502212527.1662896-1-luiz.dentz@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org From: Luiz Augusto von Dentz Currently, hci_conn_del calls hci_conn_unlink for BR/EDR, (e)SCO, and CIS connections, i.e., everything except LE connections. However, if (e)SCO connections are unlinked when BR/EDR disconnects, CIS connections should also be unlinked when LE disconnects. In terms of disconnection behavior, CIS and (e)SCO connections are not too different. One peculiarity of CIS is that when CIS connections are disconnected, the CIS handle isn't deleted, as per [BLUETOOTH CORE SPECIFICATION Version 5.4 | Vol 4, Part E] 7.1.6 Disconnect command: All SCO, eSCO, and CIS connections on a physical link should be disconnected before the ACL connection on the same physical connection is disconnected. If it does not, they will be implicitly disconnected as part of the ACL disconnection. ... Note: As specified in Section 7.7.5, on the Central, the handle for a CIS remains valid even after disconnection and, therefore, the Host can recreate a disconnected CIS at a later point in time using the same connection handle. Since hci_conn_link invokes both hci_conn_get and hci_conn_hold, hci_conn_unlink should perform both hci_conn_put and hci_conn_drop as well. However, currently it performs only hci_conn_put. This patch makes hci_conn_unlink call hci_conn_drop as well, which simplifies the logic in hci_conn_del a bit and may benefit future users of hci_conn_unlink. But it is noted that this change additionally implies that hci_conn_unlink can queue disc_work on conn itself, with the following call stack: hci_conn_unlink(conn) [conn->parent == NULL] -> hci_conn_unlink(child) [child->parent == conn] -> hci_conn_drop(child->parent) -> queue_delayed_work(&conn->disc_work) Queued disc_work after hci_conn_del can be spurious, so during the process of hci_conn_del, it is necessary to make the call to cancel_delayed_work(&conn->disc_work) after invoking hci_conn_unlink. Signed-off-by: Ruihan Li Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/hci_conn.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index ce588359b290..f75ef12f18f7 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -1100,7 +1100,9 @@ static void hci_conn_unlink(struct hci_conn *conn) * yet at this point. Delete it now, otherwise it is * possible for it to be stuck and can't be deleted. */ - if (child->handle == HCI_CONN_HANDLE_UNSET) + if ((child->type == SCO_LINK || + child->type == ESCO_LINK) && + child->handle == HCI_CONN_HANDLE_UNSET) hci_conn_del(child); } @@ -1113,6 +1115,7 @@ static void hci_conn_unlink(struct hci_conn *conn) list_del_rcu(&conn->link->list); synchronize_rcu(); + hci_conn_drop(conn->parent); hci_conn_put(conn->parent); conn->parent = NULL; @@ -1126,12 +1129,13 @@ void hci_conn_del(struct hci_conn *conn) BT_DBG("%s hcon %p handle %d", hdev->name, conn, conn->handle); + hci_conn_unlink(conn); + cancel_delayed_work_sync(&conn->disc_work); cancel_delayed_work_sync(&conn->auto_accept_work); cancel_delayed_work_sync(&conn->idle_work); if (conn->type == ACL_LINK) { - hci_conn_unlink(conn); /* Unacked frames */ hdev->acl_cnt += conn->sent; } else if (conn->type == LE_LINK) { @@ -1142,13 +1146,6 @@ void hci_conn_del(struct hci_conn *conn) else hdev->acl_cnt += conn->sent; } else { - struct hci_conn *acl = conn->parent; - - if (acl) { - hci_conn_unlink(conn); - hci_conn_drop(acl); - } - /* Unacked ISO frames */ if (conn->type == ISO_LINK) { if (hdev->iso_pkts) @@ -2485,12 +2482,6 @@ void hci_conn_hash_flush(struct hci_dev *hdev) list)) != NULL) { conn->state = BT_CLOSED; hci_disconn_cfm(conn, HCI_ERROR_LOCAL_HOST_TERM); - - /* Unlink before deleting otherwise it is possible that - * hci_conn_del removes the link which may cause the list to - * contain items already freed. - */ - hci_conn_unlink(conn); hci_conn_del(conn); } }