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 4A73CECAAD5 for ; Tue, 6 Sep 2022 14:06:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239466AbiIFOGR (ORCPT ); Tue, 6 Sep 2022 10:06:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241539AbiIFOEs (ORCPT ); Tue, 6 Sep 2022 10:04:48 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D13F8252AD; Tue, 6 Sep 2022 06:44:59 -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 ams.source.kernel.org (Postfix) with ESMTPS id 8BF8EB818C0; Tue, 6 Sep 2022 13:43:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E201AC433D6; Tue, 6 Sep 2022 13:43:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662471836; bh=BaZCLaoVmJWIPg4+A2ic5F4/q/MaPqyecEILBXQKRFs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZqPhfPqYF2ktUMFIFCLJ6EX8wEIsnne8Cuj5vFJ6Kv3RLnZPpAEQKoB6P29r2dkpQ Cbbk+yMK484oLkibmd/Mmv60U+dleJGVLJ7X0+/LayB2rLsikyZ0KU/EFbDcR/Q13o /D+INRI23Ol0NeK6/k4eoa4DmxzBtZ2h5bo898dI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Vadim Pasternak , Hans de Goede , Sasha Levin Subject: [PATCH 5.19 055/155] platform/mellanox: mlxreg-lc: Fix locking issue Date: Tue, 6 Sep 2022 15:30:03 +0200 Message-Id: <20220906132831.744423991@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220906132829.417117002@linuxfoundation.org> References: <20220906132829.417117002@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: linux-kernel@vger.kernel.org From: Vadim Pasternak [ Upstream commit 1e092b7faa6b507125b69c92a51bb22c2d549d37 ] Fix locking issues: - mlxreg_lc_state_update() takes a lock when set or clear "MLXREG_LC_POWERED". - All the devices can be deleted before MLXREG_LC_POWERED flag is cleared. To fix it: - Add lock() / unlock() at the beginning / end of mlxreg_lc_event_handler() and remove locking from mlxreg_lc_power_on_off() and mlxreg_lc_enable_disable() - Add locked version of mlxreg_lc_state_update() - mlxreg_lc_state_update_locked() for using outside mlxreg_lc_event_handler(). (2) Remove redundant NULL check for of if 'data->notifier'. Fixes: 62f9529b8d5c87b ("platform/mellanox: mlxreg-lc: Add initial support for Nvidia line card devices") Reported-by: Dan Carpenter Signed-off-by: Vadim Pasternak Link: https://lore.kernel.org/r/20220823201937.46855-3-vadimp@nvidia.com Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede Signed-off-by: Sasha Levin --- drivers/platform/mellanox/mlxreg-lc.c | 37 ++++++++++++++++++--------- 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/drivers/platform/mellanox/mlxreg-lc.c b/drivers/platform/mellanox/mlxreg-lc.c index 9a1bfcd24317d..e578c7bc060bb 100644 --- a/drivers/platform/mellanox/mlxreg-lc.c +++ b/drivers/platform/mellanox/mlxreg-lc.c @@ -460,8 +460,6 @@ static int mlxreg_lc_power_on_off(struct mlxreg_lc *mlxreg_lc, u8 action) u32 regval; int err; - mutex_lock(&mlxreg_lc->lock); - err = regmap_read(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_pwr, ®val); if (err) goto regmap_read_fail; @@ -474,7 +472,6 @@ static int mlxreg_lc_power_on_off(struct mlxreg_lc *mlxreg_lc, u8 action) err = regmap_write(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_pwr, regval); regmap_read_fail: - mutex_unlock(&mlxreg_lc->lock); return err; } @@ -491,8 +488,6 @@ static int mlxreg_lc_enable_disable(struct mlxreg_lc *mlxreg_lc, bool action) * line card which is already has been enabled. Disabling does not affect the disabled line * card. */ - mutex_lock(&mlxreg_lc->lock); - err = regmap_read(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_ena, ®val); if (err) goto regmap_read_fail; @@ -505,7 +500,6 @@ static int mlxreg_lc_enable_disable(struct mlxreg_lc *mlxreg_lc, bool action) err = regmap_write(mlxreg_lc->par_regmap, mlxreg_lc->data->reg_ena, regval); regmap_read_fail: - mutex_unlock(&mlxreg_lc->lock); return err; } @@ -537,6 +531,15 @@ mlxreg_lc_sn4800_c16_config_init(struct mlxreg_lc *mlxreg_lc, void *regmap, static void mlxreg_lc_state_update(struct mlxreg_lc *mlxreg_lc, enum mlxreg_lc_state state, u8 action) +{ + if (action) + mlxreg_lc->state |= state; + else + mlxreg_lc->state &= ~state; +} + +static void +mlxreg_lc_state_update_locked(struct mlxreg_lc *mlxreg_lc, enum mlxreg_lc_state state, u8 action) { mutex_lock(&mlxreg_lc->lock); @@ -560,8 +563,11 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind, dev_info(mlxreg_lc->dev, "linecard#%d state %d event kind %d action %d\n", mlxreg_lc->data->slot, mlxreg_lc->state, kind, action); - if (!(mlxreg_lc->state & MLXREG_LC_INITIALIZED)) + mutex_lock(&mlxreg_lc->lock); + if (!(mlxreg_lc->state & MLXREG_LC_INITIALIZED)) { + mutex_unlock(&mlxreg_lc->lock); return 0; + } switch (kind) { case MLXREG_HOTPLUG_LC_SYNCED: @@ -574,7 +580,7 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind, if (!(mlxreg_lc->state & MLXREG_LC_POWERED) && action) { err = mlxreg_lc_power_on_off(mlxreg_lc, 1); if (err) - return err; + goto mlxreg_lc_power_on_off_fail; } /* In case line card is configured - enable it. */ if (mlxreg_lc->state & MLXREG_LC_CONFIGURED && action) @@ -588,12 +594,13 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind, /* In case line card is configured - enable it. */ if (mlxreg_lc->state & MLXREG_LC_CONFIGURED) err = mlxreg_lc_enable_disable(mlxreg_lc, 1); + mutex_unlock(&mlxreg_lc->lock); return err; } err = mlxreg_lc_create_static_devices(mlxreg_lc, mlxreg_lc->main_devs, mlxreg_lc->main_devs_num); if (err) - return err; + goto mlxreg_lc_create_static_devices_fail; /* In case line card is already in ready state - enable it. */ if (mlxreg_lc->state & MLXREG_LC_CONFIGURED) @@ -620,6 +627,10 @@ static int mlxreg_lc_event_handler(void *handle, enum mlxreg_hotplug_kind kind, break; } +mlxreg_lc_power_on_off_fail: +mlxreg_lc_create_static_devices_fail: + mutex_unlock(&mlxreg_lc->lock); + return err; } @@ -665,7 +676,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent, if (err) goto mlxreg_lc_create_static_devices_failed; - mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_POWERED, 1); + mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_POWERED, 1); } /* Verify if line card is synchronized. */ @@ -676,7 +687,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent, /* Power on line card if necessary. */ if (regval & mlxreg_lc->data->mask) { mlxreg_lc->state |= MLXREG_LC_SYNCED; - mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_SYNCED, 1); + mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_SYNCED, 1); if (mlxreg_lc->state & ~MLXREG_LC_POWERED) { err = mlxreg_lc_power_on_off(mlxreg_lc, 1); if (err) @@ -684,7 +695,7 @@ static int mlxreg_lc_completion_notify(void *handle, struct i2c_adapter *parent, } } - mlxreg_lc_state_update(mlxreg_lc, MLXREG_LC_INITIALIZED, 1); + mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_INITIALIZED, 1); return 0; @@ -904,6 +915,8 @@ static int mlxreg_lc_remove(struct platform_device *pdev) struct mlxreg_core_data *data = dev_get_platdata(&pdev->dev); struct mlxreg_lc *mlxreg_lc = platform_get_drvdata(pdev); + mlxreg_lc_state_update_locked(mlxreg_lc, MLXREG_LC_INITIALIZED, 0); + /* * Probing and removing are invoked by hotplug events raised upon line card insertion and * removing. If probing procedure fails all data is cleared. However, hotplug event still -- 2.35.1