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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DE1FECE58C for ; Mon, 7 Oct 2019 14:10:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 013CF206C2 for ; Mon, 7 Oct 2019 14:10:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b="DMSgVurA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728175AbfJGOKY (ORCPT ); Mon, 7 Oct 2019 10:10:24 -0400 Received: from nbd.name ([46.4.11.11]:59050 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727744AbfJGOKY (ORCPT ); Mon, 7 Oct 2019 10:10:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=References:In-Reply-To:Message-Id:Date:Subject:To:From:Sender: Reply-To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=xpsgVLAhty0xvbV0v5NJk/FBqH3pVGiT5oePlgM8iSU=; b=DMSgVurAX8HNMH6L0YNq6U/muA opNe0su59G0VNIwOd9eTLJIQOuIwOcSfLCqbO06hSkAjPQPp5KNdhsEkUUFeW8quvxR54grBFOjN7 QQU3zBUfi5VWlILsZcyC62sHuKPqXlbQcT1peSln74wN8Sh8UZF3uyfg1ThrHmny4uRo=; Received: from p54ae9582.dip0.t-ipconnect.de ([84.174.149.130] helo=maeck.lan) by ds12 with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iHTiQ-0002Wo-Um for linux-wireless@vger.kernel.org; Mon, 07 Oct 2019 16:10:23 +0200 Received: by maeck.lan (Postfix, from userid 501) id 5B6E46AB2C99; Mon, 7 Oct 2019 16:10:22 +0200 (CEST) From: Felix Fietkau To: linux-wireless@vger.kernel.org Subject: [PATCH 2/4] mt76: drop rcu read lock in mt76_rx_aggr_stop Date: Mon, 7 Oct 2019 16:10:20 +0200 Message-Id: <20191007141022.75184-2-nbd@nbd.name> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20191007141022.75184-1-nbd@nbd.name> References: <20191007141022.75184-1-nbd@nbd.name> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org A rcu read locked section is not allowed to sleep, and the rcu lock here isn't actually necessary, because we're holding dev->mutex. Fixes an issue when the tid work item is still running while freeing a station or stopping the aggregation session Signed-off-by: Felix Fietkau --- drivers/net/wireless/mediatek/mt76/agg-rx.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/agg-rx.c b/drivers/net/wireless/mediatek/mt76/agg-rx.c index 2276fd4e9ec3..b05d439dca3b 100644 --- a/drivers/net/wireless/mediatek/mt76/agg-rx.c +++ b/drivers/net/wireless/mediatek/mt76/agg-rx.c @@ -277,17 +277,13 @@ static void mt76_rx_aggr_shutdown(struct mt76_dev *dev, struct mt76_rx_tid *tid) void mt76_rx_aggr_stop(struct mt76_dev *dev, struct mt76_wcid *wcid, u8 tidno) { - struct mt76_rx_tid *tid; - - rcu_read_lock(); + struct mt76_rx_tid *tid = NULL; - tid = rcu_dereference(wcid->aggr[tidno]); + rcu_swap_protected(wcid->aggr[tidno], tid, + lockdep_is_held(&dev->mutex)); if (tid) { - rcu_assign_pointer(wcid->aggr[tidno], NULL); mt76_rx_aggr_shutdown(dev, tid); kfree_rcu(tid, rcu_head); } - - rcu_read_unlock(); } EXPORT_SYMBOL_GPL(mt76_rx_aggr_stop); -- 2.17.0