From patchwork Mon Sep 21 14:43:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank Heimes X-Patchwork-Id: 1368459 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Bw6dc0KMgz9sX3; Tue, 22 Sep 2020 00:44:03 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1kKN2u-0006Xo-Td; Mon, 21 Sep 2020 14:44:00 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kKN2u-0006Xe-3M for kernel-team@lists.ubuntu.com; Mon, 21 Sep 2020 14:44:00 +0000 Received: from 2.general.fheimes.uk.vpn ([10.172.194.67] helo=T570.fritz.box) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kKN2t-0003XY-Qu for kernel-team@lists.ubuntu.com; Mon, 21 Sep 2020 14:43:59 +0000 From: frank.heimes@canonical.com To: kernel-team@lists.ubuntu.com Subject: [SRU][F][PATCH 1/1] s390/pci: fix leak of DMA tables on hard unplug Date: Mon, 21 Sep 2020 16:43:43 +0200 Message-Id: <20200921144343.724633-2-frank.heimes@canonical.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200921144343.724633-1-frank.heimes@canonical.com> References: <20200921144343.724633-1-frank.heimes@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Niklas Schnelle BugLink: https://bugs.launchpad.net/bugs/1896216 commit f606b3ef47c9 ("s390/pci: adapt events for zbus") removed the zpci_disable_device() call for a zPCI event with PEC 0x0304 because the device is already deconfigured by the platform. This however skips the Linux side of the disable in particular it leads to leaking the DMA tables and bitmaps because zpci_dma_exit_device() is never called on the device. If the device transitions to the Reserved state we call zpci_zdev_put() but zpci_release_device() will not call zpci_disable_device() because the state of the zPCI function is already ZPCI_FN_STATE_STANDBY. If the device is put into the Standby state, zpci_disable_device() is not called and the device is assumed to have been put in Standby through platform action. At this point the device may be removed by a subsequent event with PEC 0x0308 or 0x0306 which calls zpci_zdev_put() with the same problem as above or the device may be configured again in which case zpci_disable_device() is also not called. Fix this by calling zpci_disable_device() explicitly for PEC 0x0304 as before. To make it more clear that zpci_disable_device() may be called, even if the lower level device has already been disabled by the platform, add a comment to zpci_disable_device(). Cc: # 5.8 Fixes: f606b3ef47c9 ("s390/pci: adapt events for zbus") Signed-off-by: Niklas Schnelle Signed-off-by: Vasily Gorbik (cherry picked from commit afdf9550e54627fcf4dd609bdc1153059378cdf5 linux-next) Signed-off-by: Frank Heimes Acked-by: Stefan Bader --- arch/s390/pci/pci.c | 4 ++++ arch/s390/pci/pci_event.c | 2 ++ 2 files changed, 6 insertions(+) diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c index fb25665ec44b..f3a477f919d0 100644 --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -709,6 +709,10 @@ EXPORT_SYMBOL_GPL(zpci_enable_device); int zpci_disable_device(struct zpci_dev *zdev) { zpci_dma_exit_device(zdev); + /* + * The zPCI function may already be disabled by the platform, this is + * detected in clp_disable_fh() which becomes a no-op. + */ return clp_disable_fh(zdev); } EXPORT_SYMBOL_GPL(zpci_disable_device); diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c index 9a3a291cad43..d9ae7456dd4c 100644 --- a/arch/s390/pci/pci_event.c +++ b/arch/s390/pci/pci_event.c @@ -143,6 +143,8 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf) zpci_remove_device(zdev); } + zdev->fh = ccdf->fh; + zpci_disable_device(zdev); zdev->state = ZPCI_FN_STATE_STANDBY; if (!clp_get_state(ccdf->fid, &state) && state == ZPCI_FN_STATE_RESERVED) {