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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 4FDABC4727E for ; Wed, 7 Oct 2020 15:43:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBCBD21775 for ; Wed, 7 Oct 2020 15:43:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="F/1PO7iF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727912AbgJGPnb (ORCPT ); Wed, 7 Oct 2020 11:43:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727005AbgJGPnb (ORCPT ); Wed, 7 Oct 2020 11:43:31 -0400 Received: from mail-il1-x142.google.com (mail-il1-x142.google.com [IPv6:2607:f8b0:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0743EC0613D2; Wed, 7 Oct 2020 08:43:31 -0700 (PDT) Received: by mail-il1-x142.google.com with SMTP id o18so2716408ill.2; Wed, 07 Oct 2020 08:43:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=XLErf/pxRiqNYirhZZuvmNaePRdLyo9kzRk5xrxoNiI=; b=F/1PO7iFtNNGiOo3iYB+K5B7xcDy2INnmOBSZYzckiMBh17YWO0eKjV4ZbAmaF+PJG lmIDh+tYXMQBO7uIbPfhsLtN4dKK73NvU+BBV2UmF4/MLzSM7WtBqxZlaFDCR3tT9wij QGiE5hcGAzgoPc2nlqOBlIWw2kNy0dOHOetnz1ElQL0C1ePUHMvK/+BTae7SA6VkZLh3 ztKtPEH6QmFohzNxF8DCntb4fq6YjmzO37mXUVxjiDC8vKH0pkzn9rwqm2S+C0X3MKUR nrCR9lKmPNRIKUTeZslyyuAH2deKfGRDPfJudrF+RFjHaoSxMME2+rYXXQs63clGchXl 1PnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=XLErf/pxRiqNYirhZZuvmNaePRdLyo9kzRk5xrxoNiI=; b=WUqBItBCgVuU0qpVM/FdfpBRQH0tAIpYgEtHvc1c1/47Oozg5M2yZImPuAKGx39Nhc DholGHfKH9zJpNsHssV9id5nPXxnEZ2VE0Z6aYQ/ttSi2AgMkarH+2yDtY27Iv1LMDaW tKaBg9B7sMexDIXvyP4Lxp5TCt2Df4wPE6b5+LdM332uwZStgTt3dkjXGeFD2ksq5b+k lATZtSJDUB2h7ES23S9HxRyZ1s8oXtP/CWrWCkePmh71ayD3Xk9+xg8ZZGmz3kgh+j52 rSiUlviYN9qbZ3URDElKWjaaSYf5mUEg94bsjTd7YyDD9T7zHqTJ6lRagSKXb1pNg0NS 0pAw== X-Gm-Message-State: AOAM5319gmHiKuZHpqZDfZtkp41A/Kpq2utCKNQi1VwmvcgN07CwzToK 1KSUdh7fmagKjJjPPwoZ33zI1k9tj0X1AVGg6gg= X-Google-Smtp-Source: ABdhPJzYG90VRk4VCTsbGZMwSv6suXz1iFPnQuwpl76x3sjHbZu6JHgGEJ9Uxe3HE95st0zaTrE2TVDgocp+nbNvCUc= X-Received: by 2002:a92:8910:: with SMTP id n16mr3335377ild.239.1602085410239; Wed, 07 Oct 2020 08:43:30 -0700 (PDT) MIME-Version: 1.0 References: <20200928114445.19689-1-sudeep.holla@arm.com> <20200928114445.19689-5-sudeep.holla@arm.com> <20201007114034.rkiujybiknaedy7m@bogus> In-Reply-To: <20201007114034.rkiujybiknaedy7m@bogus> From: Jassi Brar Date: Wed, 7 Oct 2020 10:43:19 -0500 Message-ID: Subject: Re: [PATCH 4/4] mailbox: arm_mhu: Add ARM MHU doorbell driver To: Sudeep Holla Cc: Jassi Brar , Viresh Kumar , ALKML , DTML , LKML , Vincent Guittot , Frank Rowand , Bjorn Andersson , Rob Herring , Rob Herring Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Wed, Oct 7, 2020 at 6:40 AM Sudeep Holla wrote: > > On Fri, Oct 02, 2020 at 02:42:37PM -0500, Jassi Brar wrote: > > On Mon, Sep 28, 2020 at 6:45 AM Sudeep Holla wrote: > > > > > + > > > +static void mhu_db_shutdown(struct mbox_chan *chan) > > > +{ > > > + struct mhu_db_channel *chan_info = chan->con_priv; > > > + struct mbox_controller *mbox = &chan_info->mhu->mbox; > > > + int i; > > > + > > > + for (i = 0; i < mbox->num_chans; i++) > > > + if (chan == &mbox->chans[i]) > > > + break; > > > + > > > + if (mbox->num_chans == i) { > > > + dev_warn(mbox->dev, "Request to free non-existent channel\n"); > > > + return; > > > + } > > > + > > > + /* Reset channel */ > > > + mhu_db_mbox_clear_irq(chan); > > > + chan->con_priv = NULL; > > > > > request->free->request will fail because of this NULL assignment. > > Maybe add a 'taken' flag in mhu_db_channel, which should also be > > checked before calling mbox_chan_received_data because the data may > > arrive for a now relinquished channel. > > > > Good point, but the new 'taken' flag will have the same race as con_priv. > We need a lock here and can we use chan->lock or do you prefer this > driver maintains it own for this purpose. > I meant the con_priv is allocated in mhu_db_mbox_xlate and simply assigning it NULL leaks memory, if not a crash by some other path. At least free it before. -j