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=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 5221BC43603 for ; Thu, 19 Dec 2019 12:04:18 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 23E93222C2 for ; Thu, 19 Dec 2019 12:04:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="fSl4t6pZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23E93222C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id D4B4787F08; Thu, 19 Dec 2019 12:04:17 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id I17Yf2Whetwd; Thu, 19 Dec 2019 12:04:17 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 37E9A87F00; Thu, 19 Dec 2019 12:04:17 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 157F9C18DC; Thu, 19 Dec 2019 12:04:17 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 69918C077D for ; Thu, 19 Dec 2019 12:04:16 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 580D187F04 for ; Thu, 19 Dec 2019 12:04:16 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id VPxeT3ZD7uvg for ; Thu, 19 Dec 2019 12:04:15 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by whitealder.osuosl.org (Postfix) with ESMTPS id B794A87F00 for ; Thu, 19 Dec 2019 12:04:15 +0000 (UTC) Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 38F3924650; Thu, 19 Dec 2019 12:04:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576757055; bh=HgXtsgN6xVx39MU4q6JvdB/g0TZMwtT2d6vaIKJJ5e4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fSl4t6pZfzElFVqBe6knTYDJ8hQQJN06DOMfiZ24+Lj+iTbPaX1gp9MPVlH7hrgLL QxOTiYz0yX822cb2EDGpEGHb2EjvtqqC2fwNoo7s6LAf4BBGLKG7LRICMjP+cI0wqx cEgub9F/yFmYnjQzP3EyF2lf5wvt8KPKsLhOfcCk= From: Will Deacon To: linux-kernel@vger.kernel.org, iommu@lists.linuxfoundation.org Subject: [PATCH v4 05/16] drivers/iommu: Take a ref to the IOMMU driver prior to ->add_device() Date: Thu, 19 Dec 2019 12:03:41 +0000 Message-Id: <20191219120352.382-6-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191219120352.382-1-will@kernel.org> References: <20191219120352.382-1-will@kernel.org> MIME-Version: 1.0 Cc: "Isaac J. Manjarres" , Jean-Philippe Brucker , Saravana Kannan , kernel-team@android.com, Robin Murphy , Greg Kroah-Hartman , Bjorn Helgaas , Will Deacon , Ard Biesheuvel X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" To avoid accidental removal of an active IOMMU driver module, take a reference to the driver module in 'iommu_probe_device()' immediately prior to invoking the '->add_device()' callback and hold it until the after the device has been removed by '->remove_device()'. Suggested-by: Joerg Roedel Signed-off-by: Will Deacon --- drivers/iommu/iommu.c | 19 +++++++++++++++++-- include/linux/iommu.h | 4 +++- 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 7c92197d53f3..bc8edf90e729 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -22,6 +22,7 @@ #include #include #include +#include #include static struct kset *iommu_group_kset; @@ -185,10 +186,21 @@ int iommu_probe_device(struct device *dev) if (!iommu_get_dev_param(dev)) return -ENOMEM; + if (!try_module_get(ops->owner)) { + ret = -EINVAL; + goto err_free_dev_param; + } + ret = ops->add_device(dev); if (ret) - iommu_free_dev_param(dev); + goto err_module_put; + + return 0; +err_module_put: + module_put(ops->owner); +err_free_dev_param: + iommu_free_dev_param(dev); return ret; } @@ -199,7 +211,10 @@ void iommu_release_device(struct device *dev) if (dev->iommu_group) ops->remove_device(dev); - iommu_free_dev_param(dev); + if (dev->iommu_param) { + module_put(ops->owner); + iommu_free_dev_param(dev); + } } static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f2223cbb5fd5..e9f94d3f7a04 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -246,9 +246,10 @@ struct iommu_iotlb_gather { * @sva_get_pasid: Get PASID associated to a SVA handle * @page_response: handle page request response * @cache_invalidate: invalidate translation caches - * @pgsize_bitmap: bitmap of all possible supported page sizes * @sva_bind_gpasid: bind guest pasid and mm * @sva_unbind_gpasid: unbind guest pasid and mm + * @pgsize_bitmap: bitmap of all possible supported page sizes + * @owner: Driver module providing these ops */ struct iommu_ops { bool (*capable)(enum iommu_cap); @@ -318,6 +319,7 @@ struct iommu_ops { int (*sva_unbind_gpasid)(struct device *dev, int pasid); unsigned long pgsize_bitmap; + struct module *owner; }; /** -- 2.24.1.735.g03f4e72817-goog _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu