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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 2EA38C2D0EA for ; Wed, 8 Apr 2020 14:37:33 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F3F8B20857 for ; Wed, 8 Apr 2020 14:37:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="X72rbEUU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3F8B20857 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=fY1FKAAtrQkLXc1jIvJ+U4zke+2+gebED41CJp3angs=; b=X72rbEUUS87IDI HNtwZ4JPROy2zbSpj42JhS6CAPUT8czXZzsUHeTYJd7Hm5GoG4H96OMfSFqstsqlhmvDkDaz1mJlU RC3zFxm1jrkCx53o880DCXuzLjKeD+lRJa4c9nagsv9ftSMNj5xulXuNTnzCqY5I0lfQ4jYkHw4xK jJ9iGihgRoJeVwhKIGq4wsURGSoSBR8GypzFqhPIQT7ZvREwhAyWbiHTD4zo6crQ1huqzRIPbzrGl QeDVLxm0DicYg4QefFiImOO5XJMaW1VaZwDwVPJMmIwe/hSbwAnMCsP7T6DZ/FXNxgKaWYj5A/Lj3 p9JaWBrYUn/v19KGmlcA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jMBpN-0006bk-UN; Wed, 08 Apr 2020 14:37:17 +0000 Received: from 8bytes.org ([81.169.241.247] helo=theia.8bytes.org) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jMBpM-0006an-0I; Wed, 08 Apr 2020 14:37:17 +0000 Received: by theia.8bytes.org (Postfix, from userid 1000) id 3E3B4387; Wed, 8 Apr 2020 16:37:09 +0200 (CEST) Date: Wed, 8 Apr 2020 16:37:07 +0200 From: Joerg Roedel To: Robin Murphy Subject: Re: [RFC PATCH 17/34] iommu/arm-smmu: Store device instead of group in arm_smmu_s2cr Message-ID: <20200408143707.GK3103@8bytes.org> References: <20200407183742.4344-1-joro@8bytes.org> <20200407183742.4344-18-joro@8bytes.org> <98c10a41-d223-e375-9742-b6471c3dc33c@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <98c10a41-d223-e375-9742-b6471c3dc33c@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200408_073716_195840_E868B745 X-CRM114-Status: GOOD ( 10.83 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Heiko Stuebner , Bjorn Andersson , linux-tegra@vger.kernel.org, Thierry Reding , Will Deacon , Marek Szyprowski , Jean-Philippe Brucker , linux-samsung-soc@vger.kernel.org, Rob Clark , Krzysztof Kozlowski , Jonathan Hunter , linux-rockchip@lists.infradead.org, Andy Gross , Joerg Roedel , linux-s390@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mediatek@lists.infradead.org, Matthias Brugger , virtualization@lists.linux-foundation.org, Gerald Schaefer , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Kukjin Kim , David Woodhouse , Lu Baolu Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org Hi Robin, thanks for looking into this. On Wed, Apr 08, 2020 at 01:09:40PM +0100, Robin Murphy wrote: > For a hot-pluggable bus where logical devices may share Stream IDs (like > fsl-mc), this could happen: > > create device A > iommu_probe_device(A) > iommu_device_group(A) -> alloc group X > create device B > iommu_probe_device(B) > iommu_device_group(A) -> lookup returns group X > ... > iommu_remove_device(A) > delete device A > create device C > iommu_probe_device(C) > iommu_device_group(C) -> use-after-free of A > > Preserving the logical behaviour here would probably look *something* like > the mangled diff below, but I haven't thought it through 100%. Yeah, I think you are right. How about just moving the loop which sets s2crs[idx].group to arm_smmu_device_group()? In that case I can drop this patch and leave the group pointer in place. Regards, Joerg _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek