From patchwork Sun Oct 8 09:54:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 13412680 X-Patchwork-Delegate: jikos@jikos.cz 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 2A91CE95A8E for ; Sun, 8 Oct 2023 09:56:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344587AbjJHJ4k (ORCPT ); Sun, 8 Oct 2023 05:56:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344603AbjJHJ4j (ORCPT ); Sun, 8 Oct 2023 05:56:39 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1FB98DF for ; Sun, 8 Oct 2023 02:55:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696758916; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=acwgmegbFXWKSqtmQPBbFfDnzH4lXgA3eWG9aKrDpEY=; b=DeBm6QWNEG+skgcMpaj7FRFfpY8pYWVMvm8K/dGk2qkNG0itibzwWktf+uSgbo5PVj0L1X O91w635i14leQtBdHNFcSlZvK1qEuMitxpgWZaqju2oRr881xykR31yx/teUs3hcor/wjf xpdgfSFiICPDLzAgvYvoaFoNUs5QHzc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-413-cFqZHP6jMW6eC51SHBNDEQ-1; Sun, 08 Oct 2023 05:55:13 -0400 X-MC-Unique: cFqZHP6jMW6eC51SHBNDEQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 31C05185A78E; Sun, 8 Oct 2023 09:55:13 +0000 (UTC) Received: from shalem.redhat.com (unknown [10.39.192.74]) by smtp.corp.redhat.com (Postfix) with ESMTP id 49DA5C15BB8; Sun, 8 Oct 2023 09:55:12 +0000 (UTC) From: Hans de Goede To: =?utf-8?q?Filipe_La=C3=ADns?= , Bastien Nocera , Jiri Kosina , Benjamin Tissoires Cc: Hans de Goede , linux-input@vger.kernel.org Subject: [PATCH v2 12/14] HID: logitech-hidpp: Fix connect event race Date: Sun, 8 Oct 2023 11:54:55 +0200 Message-ID: <20231008095458.8926-13-hdegoede@redhat.com> In-Reply-To: <20231008095458.8926-1-hdegoede@redhat.com> References: <20231008095458.8926-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org There is a connect event race in hidpp_probe() in these 2 lines: connected = hidpp_root_get_protocol_version(hidpp) == 0; atomic_set(&hidpp->connected, connected); Specifically the following can happen: 1. This line from hidpp_probe() is executed: connected = hidpp_root_get_protocol_version(hidpp) == 0; and sets connected to false; 2. A connect-event packet is received and does: atomic_set(&hidpp->connected, true); 3. The next line from hidpp_probe() is executed: atomic_set(&hidpp->connected, connected); and sets the atomic_t back to 0 again. 4. hidpp_connect_event() runs and sees the connected device as disconnected because of this. To fix this make hidpp_connect_event() query the connection status of the device itself instead of having it rely on possibly stale data cached in struct hidpp_device. Signed-off-by: Hans de Goede --- drivers/hid/hid-logitech-hidpp.c | 29 +++++++---------------------- 1 file changed, 7 insertions(+), 22 deletions(-) diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index 2b0a2ea5da22..37213dcc9d9c 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -194,7 +194,6 @@ struct hidpp_device { struct work_struct work; struct kfifo delayed_work_fifo; - atomic_t connected; struct input_dev *delayed_input; unsigned long quirks; @@ -3893,8 +3892,6 @@ static int hidpp_raw_hidpp_event(struct hidpp_device *hidpp, u8 *data, } if (unlikely(hidpp_report_is_connect_event(hidpp, report))) { - atomic_set(&hidpp->connected, - !(report->rap.params[0] & (1 << 6))); if (schedule_work(&hidpp->work) == 0) dbg_hid("%s: connect event already queued\n", __func__); return 1; @@ -4189,12 +4186,14 @@ static struct input_dev *hidpp_allocate_input(struct hid_device *hdev) static void hidpp_connect_event(struct hidpp_device *hidpp) { struct hid_device *hdev = hidpp->hid_dev; - int ret = 0; - bool connected = atomic_read(&hidpp->connected); struct input_dev *input; char *name, *devm_name; + int ret; - if (!connected) { + /* Get device version to check if it is connected */ + ret = hidpp_root_get_protocol_version(hidpp); + if (ret) { + hid_info(hidpp->hid_dev, "Disconnected\n"); if (hidpp->battery.ps) { hidpp->battery.online = false; hidpp->battery.status = POWER_SUPPLY_STATUS_UNKNOWN; @@ -4235,17 +4234,6 @@ static void hidpp_connect_event(struct hidpp_device *hidpp) if (ret) return; } - - /* the device is already connected, we can ask for its name and - * protocol */ - if (!hidpp->protocol_major) { - ret = hidpp_root_get_protocol_version(hidpp); - if (ret) { - hid_err(hdev, "Can not get the protocol version.\n"); - return; - } - } - if (hidpp->protocol_major >= 2) { u8 feature_index; @@ -4418,7 +4406,6 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) { struct hidpp_device *hidpp; int ret; - bool connected; unsigned int connect_mask = HID_CONNECT_DEFAULT; /* report_fixup needs drvdata to be set before we call hid_parse */ @@ -4511,11 +4498,9 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id) /* * Now that incoming packets are enabled and will not be disabled - * again (which may cause missing packets) check the connected state - * of the device. + * again (which may cause missing packets) queue hidpp_connect_event() + * to check the connected state of the device. */ - connected = hidpp_root_get_protocol_version(hidpp) == 0; - atomic_set(&hidpp->connected, connected); schedule_work(&hidpp->work); flush_work(&hidpp->work);