Received: by 2002:a25:1985:0:0:0:0:0 with SMTP id 127csp236667ybz; Thu, 16 Apr 2020 23:44:25 -0700 (PDT) X-Google-Smtp-Source: APiQypKPrWiIjNRI7Q2yGmj2OqQt3FkhFhrh4uIBkH+US8wZjvkKiHbcy5Br6MOb1FEA8eXh14Fv X-Received: by 2002:a05:6402:2d5:: with SMTP id b21mr1479130edx.291.1587105865146; Thu, 16 Apr 2020 23:44:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1587105865; cv=none; d=google.com; s=arc-20160816; b=sMwz8InLd2kO8/Rtuc6S6G29PCOF/sOHt0yeuOofWUblhvrP+kUOJQbPeJacYLlSXQ r/mErbCXXlEdk3baxjw04Z07IirgNaCHYfn0NuMk6u2A2PNAocWpFGi74q7MbncxFmAt 8OwVWJIxzVgTl90ACCn1y2vuCqHUgSXqMjQYhIqaoILS4O7FfQNDv/S4Y5noNOROt11D lwEgHRFvvL2tkJJwthGH4WHuExGQs1zbAYNXn7i/yhyLgMUxkGoYpvSqH3GFPkf7CM1m 1kc2izjWBkg6k6pbsd5ywkEPO/kg7AJijSOy9fLQ1Xdw0v/3BG+MZnEAxWTm6kTDbjL6 du6w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:subject:content-transfer-encoding :mime-version:user-agent:references:in-reply-to:date:cc:to:from :message-id; bh=q1cjgzCQZtBeWXQqGxobRoUOuK1NZNgU4Y6zMv/sdpI=; b=zuk0Kykr7ymjRFNSK8qajhuRBgkacbfFSQZ4zixajoFDngkd8pdCBrkF/8nssL7okp /qQ9TSNKPOAR2R0zih2nVE7lKoLZ47rc4TmRB5fOA+kolfTqq6BFCpPDbs+KKmeEKUOm +KtN0FU5GsefhKqHxg7L60mZezUgaEeBkV/DUjQQVCNP3npjhRCoP1ezyB+QDVwF07Y7 ijYWoN+kT5baOd+CopxVWg+pP7fF9OsxTqH1De8PEzwqM2Dm1UPIoTawcRXmZHENaDIh fnIPcNDcujs+HbQK8jKVWwTBYb3SJWWFoCf1kWSL1UiKK8u7EUHxjyYj7n9cPxQ8tpNs Xulw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-wireless-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id b7si8407311eju.8.2020.04.16.23.44.00; Thu, 16 Apr 2020 23:44:25 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-wireless-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728266AbgDQGmE (ORCPT + 99 others); Fri, 17 Apr 2020 02:42:04 -0400 Received: from paleale.coelho.fi ([176.9.41.70]:56350 "EHLO farmhouse.coelho.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728248AbgDQGmD (ORCPT ); Fri, 17 Apr 2020 02:42:03 -0400 Received: from 91-156-6-193.elisa-laajakaista.fi ([91.156.6.193] helo=redipa) by farmhouse.coelho.fi with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1jPKhN-000KMG-AC; Fri, 17 Apr 2020 09:42:01 +0300 Message-ID: <1c6acee636c0463c4c293ff910053f8b25b4da92.camel@coelho.fi> From: Luca Coelho To: Mark Asselstine Cc: kvalo@codeaurora.org, linux-wireless , johannes.berg@intel.com Date: Fri, 17 Apr 2020 09:42:00 +0300 In-Reply-To: References: <20200403082955.1126339-1-luca@coelho.fi> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.0-1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on farmhouse.coelho.fi X-Spam-Level: X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00, TVD_RCVD_IP autolearn=ham autolearn_force=no version=3.4.4 Subject: Re: [PATCH v5.7 8/8] iwlwifi: mvm: don't call iwl_mvm_free_inactive_queue() under RCU Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Fri, 2020-04-03 at 10:28 -0400, Mark Asselstine wrote: > I was looking into this as part of > https://bugzilla.kernel.org/show_bug.cgi?id=206971 and had a similar > fix in flight. My concern was that queue_owner being used outside of > the RCU might be an issue as now you have no guaranty that the > eventual use of sta->txq[tid] in iwl_mvm_free_inactive_queue() is > going to be valid. The only way to work around this is instead of > storing queue_owner, store mvmtxq = iwl_mvm_txq_from_tid(sta, i), then > adjust iwl_mvm_free_inactive_queue(), iwl_mvm_disable_txq() and > whatnot to take struct iwl_mvm_txq * instead of struct ieee80211_sta > *. If you open the bug you will see the latest version of my work as > the attached patch. I am not an RCU expert so I am curious to hear > your thoughts. I asked Johannes to check your comment. For now, I'm going to drop it from v2 of this patchset, so we can go ahead with the other patches. -- Cheers, Luca.