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 1A2B5C00A8F for ; Mon, 23 Oct 2023 11:09:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233573AbjJWLJX (ORCPT ); Mon, 23 Oct 2023 07:09:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233565AbjJWLJW (ORCPT ); Mon, 23 Oct 2023 07:09:22 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A782E99 for ; Mon, 23 Oct 2023 04:09:20 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAEE8C433C7; Mon, 23 Oct 2023 11:09:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698059360; bh=M3BSKEX2ahY37YgAv5jpxmUxFbKCjaBzdER2EVBP9C8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iP9FBocYe9uj8y3M/U/Jck756i7As2DNjtdg1JR8skCJGx2USt1xYou6xcFQ1uOnw 9MOebTbWIz0420FHptO6ANdhjgUc54niW8CzX87UCvIb05tMvJuUS+BvN05hHJkuGI 9xRYD3hjpqjXSBHUU5rwX/VUsiLNaWP/9QXS+QHI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Johannes Berg , Sasha Levin Subject: [PATCH 6.5 115/241] rfkill: sync before userspace visibility/changes Date: Mon, 23 Oct 2023 12:55:01 +0200 Message-ID: <20231023104836.689871403@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104833.832874523@linuxfoundation.org> References: <20231023104833.832874523@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 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg [ Upstream commit 2c3dfba4cf84ac4f306cc6653b37b6dd6859ae9d ] If userspace quickly opens /dev/rfkill after a new instance was created, it might see the old state of the instance from before the sync work runs and may even _change_ the state, only to have the sync work change it again. Fix this by doing the sync inline where needed, not just for /dev/rfkill but also for sysfs. Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/rfkill/core.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) diff --git a/net/rfkill/core.c b/net/rfkill/core.c index 01fca7a10b4bb..08630896b6c88 100644 --- a/net/rfkill/core.c +++ b/net/rfkill/core.c @@ -48,6 +48,7 @@ struct rfkill { bool persistent; bool polling_paused; bool suspended; + bool need_sync; const struct rfkill_ops *ops; void *data; @@ -368,6 +369,17 @@ static void rfkill_set_block(struct rfkill *rfkill, bool blocked) rfkill_event(rfkill); } +static void rfkill_sync(struct rfkill *rfkill) +{ + lockdep_assert_held(&rfkill_global_mutex); + + if (!rfkill->need_sync) + return; + + rfkill_set_block(rfkill, rfkill_global_states[rfkill->type].cur); + rfkill->need_sync = false; +} + static void rfkill_update_global_state(enum rfkill_type type, bool blocked) { int i; @@ -730,6 +742,10 @@ static ssize_t soft_show(struct device *dev, struct device_attribute *attr, { struct rfkill *rfkill = to_rfkill(dev); + mutex_lock(&rfkill_global_mutex); + rfkill_sync(rfkill); + mutex_unlock(&rfkill_global_mutex); + return sysfs_emit(buf, "%d\n", (rfkill->state & RFKILL_BLOCK_SW) ? 1 : 0); } @@ -751,6 +767,7 @@ static ssize_t soft_store(struct device *dev, struct device_attribute *attr, return -EINVAL; mutex_lock(&rfkill_global_mutex); + rfkill_sync(rfkill); rfkill_set_block(rfkill, state); mutex_unlock(&rfkill_global_mutex); @@ -783,6 +800,10 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr, { struct rfkill *rfkill = to_rfkill(dev); + mutex_lock(&rfkill_global_mutex); + rfkill_sync(rfkill); + mutex_unlock(&rfkill_global_mutex); + return sysfs_emit(buf, "%d\n", user_state_from_blocked(rfkill->state)); } @@ -805,6 +826,7 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr, return -EINVAL; mutex_lock(&rfkill_global_mutex); + rfkill_sync(rfkill); rfkill_set_block(rfkill, state == RFKILL_USER_STATE_SOFT_BLOCKED); mutex_unlock(&rfkill_global_mutex); @@ -1032,14 +1054,10 @@ static void rfkill_uevent_work(struct work_struct *work) static void rfkill_sync_work(struct work_struct *work) { - struct rfkill *rfkill; - bool cur; - - rfkill = container_of(work, struct rfkill, sync_work); + struct rfkill *rfkill = container_of(work, struct rfkill, sync_work); mutex_lock(&rfkill_global_mutex); - cur = rfkill_global_states[rfkill->type].cur; - rfkill_set_block(rfkill, cur); + rfkill_sync(rfkill); mutex_unlock(&rfkill_global_mutex); } @@ -1087,6 +1105,7 @@ int __must_check rfkill_register(struct rfkill *rfkill) round_jiffies_relative(POLL_INTERVAL)); if (!rfkill->persistent || rfkill_epo_lock_active) { + rfkill->need_sync = true; schedule_work(&rfkill->sync_work); } else { #ifdef CONFIG_RFKILL_INPUT @@ -1171,6 +1190,7 @@ static int rfkill_fop_open(struct inode *inode, struct file *file) ev = kzalloc(sizeof(*ev), GFP_KERNEL); if (!ev) goto free; + rfkill_sync(rfkill); rfkill_fill_event(&ev->ev, rfkill, RFKILL_OP_ADD); list_add_tail(&ev->list, &data->events); } -- 2.40.1