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 5CD0EC7EE2F for ; Sun, 28 May 2023 19:21:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229926AbjE1TVV (ORCPT ); Sun, 28 May 2023 15:21:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229931AbjE1TVT (ORCPT ); Sun, 28 May 2023 15:21:19 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA074A0 for ; Sun, 28 May 2023 12:21:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 78B7061B08 for ; Sun, 28 May 2023 19:21:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97A9DC433EF; Sun, 28 May 2023 19:21:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1685301677; bh=FakvNTWsn7i5XB9LZN4HX1OsWA/vN4W++9vq14tfdBA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FqLLk7Pl8zLF6WaLmaZcrUQ+4Mi8941nrD/QuduMTm7nJYt3NNrSa7bqMkkkL420J WG2nILetpJRgGUzL3qogggfeHvdYaxIqLkePkK5NJzTBaep4EMqJ8y3KhUCQ68uLZF 3iBPigcgjWaMNIjFRBJXWUADuJc8ykBHCwh+ocfg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hans de Goede , Sebastian Reichel Subject: [PATCH 4.19 125/132] power: supply: bq27xxx: Fix poll_interval handling and races on remove Date: Sun, 28 May 2023 20:11:04 +0100 Message-Id: <20230528190837.680147014@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230528190833.565872088@linuxfoundation.org> References: <20230528190833.565872088@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Hans de Goede commit c00bc80462afc7963f449d7f21d896d2f629cacc upstream. Before this patch bq27xxx_battery_teardown() was setting poll_interval = 0 to avoid bq27xxx_battery_update() requeuing the delayed_work item. There are 2 problems with this: 1. If the driver is unbound through sysfs, rather then the module being rmmod-ed, this changes poll_interval unexpectedly 2. This is racy, after it being set poll_interval could be changed before bq27xxx_battery_update() checks it through /sys/module/bq27xxx_battery/parameters/poll_interval Fix this by added a removed attribute to struct bq27xxx_device_info and using that instead of setting poll_interval to 0. There also is another poll_interval related race on remove(), writing /sys/module/bq27xxx_battery/parameters/poll_interval will requeue the delayed_work item for all devices on the bq27xxx_battery_devices list and the device being removed was only removed from that list after cancelling the delayed_work item. Fix this by moving the removal from the bq27xxx_battery_devices list to before cancelling the delayed_work item. Fixes: 8cfaaa811894 ("bq27x00_battery: Fix OOPS caused by unregistring bq27x00 driver") Signed-off-by: Hans de Goede Signed-off-by: Sebastian Reichel Signed-off-by: Greg Kroah-Hartman --- drivers/power/supply/bq27xxx_battery.c | 22 +++++++++------------- include/linux/power/bq27xxx_battery.h | 1 + 2 files changed, 10 insertions(+), 13 deletions(-) --- a/drivers/power/supply/bq27xxx_battery.c +++ b/drivers/power/supply/bq27xxx_battery.c @@ -1600,7 +1600,7 @@ static void bq27xxx_battery_update_unloc di->last_update = jiffies; - if (poll_interval > 0) + if (!di->removed && poll_interval > 0) mod_delayed_work(system_wq, &di->work, poll_interval * HZ); } @@ -1917,22 +1917,18 @@ EXPORT_SYMBOL_GPL(bq27xxx_battery_setup) void bq27xxx_battery_teardown(struct bq27xxx_device_info *di) { - /* - * power_supply_unregister call bq27xxx_battery_get_property which - * call bq27xxx_battery_poll. - * Make sure that bq27xxx_battery_poll will not call - * schedule_delayed_work again after unregister (which cause OOPS). - */ - poll_interval = 0; - - cancel_delayed_work_sync(&di->work); - - power_supply_unregister(di->bat); - mutex_lock(&bq27xxx_list_lock); list_del(&di->list); mutex_unlock(&bq27xxx_list_lock); + /* Set removed to avoid bq27xxx_battery_update() re-queuing the work */ + mutex_lock(&di->lock); + di->removed = true; + mutex_unlock(&di->lock); + + cancel_delayed_work_sync(&di->work); + + power_supply_unregister(di->bat); mutex_destroy(&di->lock); } EXPORT_SYMBOL_GPL(bq27xxx_battery_teardown); --- a/include/linux/power/bq27xxx_battery.h +++ b/include/linux/power/bq27xxx_battery.h @@ -63,6 +63,7 @@ struct bq27xxx_device_info { struct bq27xxx_access_methods bus; struct bq27xxx_reg_cache cache; int charge_design_full; + bool removed; unsigned long last_update; struct delayed_work work; struct power_supply *bat;