From patchwork Tue Oct 27 22:54:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 11862131 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0A588139F for ; Tue, 27 Oct 2020 22:56:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E12B22076D for ; Tue, 27 Oct 2020 22:56:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="S1Go9+9X"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="gge+wRRs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1832604AbgJ0W40 (ORCPT ); Tue, 27 Oct 2020 18:56:26 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:50108 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1832549AbgJ0W4A (ORCPT ); Tue, 27 Oct 2020 18:56:00 -0400 From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603839358; 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=SYBcnGuL2Fv6XeYcZjE3LkVMNVEGa0a3exz1vREKTcg=; b=S1Go9+9Xp1GErdJCi+ANF4TEINcRzr4AAM9/EjAfOm4GEAFc0SAG0j54/KDBMytSqwvQfq RGUaLHTTjqE0QRPwHdSY+UdOuUmep7RPNXzM9oAi28hssNsjf7kGpFSOVeeC1JUfcKe6tz bR/M0svDfG+smM3ZkcyuGLBREabdElvv/1cqPEpYchufXaGju3kscLwxVoombjHcDLxGdO oqwvAjv2MmmHX2ZyDbISyl2mOuqmVj4hqglUIjxYCWCaCuU8KT/Chcnr+/MNAaCO88JXQr vI1oB6Vkr8DY8OB3gr9Gp9LXg4bJyq5R50D4HAWZbvQWxrJvOHM+5ztGg+8i2g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603839358; 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=SYBcnGuL2Fv6XeYcZjE3LkVMNVEGa0a3exz1vREKTcg=; b=gge+wRRsIsf6uzGIOrNEXhKbIkqdyeWoXun2w3tqw/cLzNfabNyfNxT4gS/Gwym/a3kk4u vFpUXoU8eg4F39DA== To: netdev@vger.kernel.org Cc: Aymen Sghaier , Daniel Drake , "David S. Miller" , Herbert Xu , =?utf-8?q?Horia_Geant=C4=83?= , Jakub Kicinski , Jon Mason , Jouni Malinen , Kalle Valo , Leon Romanovsky , linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-rdma@vger.kernel.org, linux-wireless@vger.kernel.org, Li Yang , Madalin Bucur , Ping-Ke Shih , Rain River , Saeed Mahameed , Samuel Chessman , Ulrich Kunitz , Zhu Yanjun , Thomas Gleixner , Sebastian Andrzej Siewior Subject: [PATCH net-next 11/15] net: rtlwifi: Remove in_interrupt() usage in is_any_client_connect_to_ap(). Date: Tue, 27 Oct 2020 23:54:50 +0100 Message-Id: <20201027225454.3492351-12-bigeasy@linutronix.de> In-Reply-To: <20201027225454.3492351-1-bigeasy@linutronix.de> References: <20201027225454.3492351-1-bigeasy@linutronix.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org is_any_client_connect_to_ap() is using in_interrupt() to determine whether it should acquire the lock prior accessing the list. The usage of in_interrupt() in drivers is phased out and Linus clearly requested that code which changes behaviour depending on context should either be separated or the context be conveyed in an argument passed by the caller, which usually knows the context. The function is called from: - halbtc_get() - halbtc_get() halbtc_get_wifi_link_status() - halbtc_display_dbg_msg() halbtc_display_wifi_status() halbtc_get_wifi_link_status() All top level callers are part of the btc_coexist callback inferface and are never invoked from a context which can hold the lock already. The contexts which hold the lock are either protecting list add/del operations or list walks which never call into any of the btc_coexist interfaces. In fact the conditional is outright dangerous because if this function would be invoked from a BH disabled context the check would avoid taking the lock while on another CPU the list could be manipulated under the lock. Remove the in_interrupt() check and always acquire the lock. To simplify the code further use list_empty() instead of walking the list and counting the entries just to check the count for > 0 at the end. Signed-off-by: Sebastian Andrzej Siewior Cc: Ping-Ke Shih Cc: Kalle Valo Cc: "David S. Miller" Cc: Jakub Kicinski Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org --- .../realtek/rtlwifi/btcoexist/halbtcoutsrc.c | 25 +++++-------------- 1 file changed, 6 insertions(+), 19 deletions(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c b/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c index 2c05369b79e4d..2155a6699ef8d 100644 --- a/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c +++ b/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c @@ -47,30 +47,17 @@ static bool is_any_client_connect_to_ap(struct btc_coexist *btcoexist) { struct rtl_priv *rtlpriv = btcoexist->adapter; struct rtl_mac *mac = rtl_mac(rtlpriv); - struct rtl_sta_info *drv_priv; - u8 cnt = 0; + bool ret = false; if (mac->opmode == NL80211_IFTYPE_ADHOC || mac->opmode == NL80211_IFTYPE_MESH_POINT || mac->opmode == NL80211_IFTYPE_AP) { - if (in_interrupt() > 0) { - list_for_each_entry(drv_priv, &rtlpriv->entry_list, - list) { - cnt++; - } - } else { - spin_lock_bh(&rtlpriv->locks.entry_list_lock); - list_for_each_entry(drv_priv, &rtlpriv->entry_list, - list) { - cnt++; - } - spin_unlock_bh(&rtlpriv->locks.entry_list_lock); - } + spin_lock_bh(&rtlpriv->locks.entry_list_lock); + if (!list_empty(&rtlpriv->entry_list)) + ret = true; + spin_unlock_bh(&rtlpriv->locks.entry_list_lock); } - if (cnt > 0) - return true; - else - return false; + return ret; } static bool halbtc_legacy(struct rtl_priv *adapter)