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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD847C4332F for ; Mon, 13 Nov 2023 21:22:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229715AbjKMVWZ (ORCPT ); Mon, 13 Nov 2023 16:22:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231549AbjKMVWY (ORCPT ); Mon, 13 Nov 2023 16:22:24 -0500 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E09AD5F for ; Mon, 13 Nov 2023 13:22:18 -0800 (PST) Received: by mail-pf1-x434.google.com with SMTP id d2e1a72fcca58-6c10f098a27so3792506b3a.2 for ; Mon, 13 Nov 2023 13:22:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; t=1699910538; x=1700515338; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=yB03TM17vbvhZT58Q2SS4TczGT9i9Qi7UUIkyHhWl3M=; b=Ldo4Z2pU+waYj5RtdeGrDbvroVPlUq8J8DEnVH0GfzET10oqzBOr/nf6Qo8UEMrh10 gfyBBaGc79GHRmGawWd4L4Pkln4KKO9iaQrykAnIX/XyQhu2vPI6BbhB722mnmsLbB2L VGE86C3OyILzC0luNST/JRy1S+M21m4Qz0aQGFrQmfNa2ojUTPZnyf1kc5ccaRn4U2Rm OfYr6UX+0trkqT4XSaGYlC56GX+rYgFFuk9Z6z+zcnbCVk1aT9UGTjsmxwHXICTM5RAX za9VLbPs/TZKIqsEg8vhTfv5u+1S5KPuE3WIL5R2Z4D5ZtxmWNHGReWgdGCtOypcnGHT Uq2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699910538; x=1700515338; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=yB03TM17vbvhZT58Q2SS4TczGT9i9Qi7UUIkyHhWl3M=; b=pqxEIvr0F6QR9sOsT4JdSxo2DhosWmhUOPRR4Ulc1EoThMSgdsBN3SJldZdjbqgzU5 t3lP5/ji0AjHn/XX9t5H5UCRFdR84zCNVV6aYXSeVF/oD9UVBZu4Is15n8+oej8IuvS9 y3oCS3xl7obZwHP/sPaEr1dqPKs3Ub+0QcL+wFnyMzngh+mjQd/ZFUy+MrYMEJXwQMH6 PMsfgqJf1LhBn998Z1zw/PYVlrVmrdsfdGj+5KOA9+2qzZqRvWJorsY1TGvsVjQUiG5n eF1zXnZe6SHQxHqe5L7TiQifqc9i/mkBBkfQzRH+lxS3pTnQIJHN/jikr3GJ4NFK9XWG 2JZQ== X-Gm-Message-State: AOJu0YxbDVwozg1V7K8mA7tD2U3nrgoyTw+kG4ur95S+CDIPPZO+5DGY O28v74yKNYGUCHirXy+MSBS8XA== X-Google-Smtp-Source: AGHT+IHAexnOpgT0lxSAqBoHrrQk3kG4fyHEKqFXoZeiD6gfuKu33avIXHhES5sba9dXZTo05sZNBA== X-Received: by 2002:a05:6a00:6c8c:b0:68e:380c:6b15 with SMTP id jc12-20020a056a006c8c00b0068e380c6b15mr6939189pfb.26.1699910537806; Mon, 13 Nov 2023 13:22:17 -0800 (PST) Received: from dns-b876885-0.sjc.aristanetworks.com ([74.123.28.14]) by smtp.gmail.com with ESMTPSA id k17-20020aa792d1000000b006bc3e8f58besm38794pfa.56.2023.11.13.13.22.16 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Nov 2023 13:22:17 -0800 (PST) From: Daniel Stodden To: Kurt Schwemmer , Logan Gunthorpe , linux-pci@vger.kernel.org Cc: Daniel Stodden Subject: [PATCH v3 0/1] switchtec: Fix stdev_release crash after suprise device loss. Date: Mon, 13 Nov 2023 13:21:49 -0800 Message-ID: <20231113212150.96410-1-dns@arista.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hello. Changes since v2: * Inline/remove disable_dma_mrpc. * Reviewed-by: Logan Gunthorpe Here goes a small shell script to crash a kernel in switchtec.ko's stdev_release. --snip-- #!/bin/bash -x # open cdev exec 3<>/dev/switchtec0 # remove pdev addr=$(basename $(realpath /sys/class/switchtec/switchtec0/../..)) echo 1 > /sys/bus/pci/devices/$addr/remove # close cdev exec 3>&- --snip-- It worked on v5.10. I believe it has been working ever since. The problem is that keeping the stdev pinned past the pci_driver removal will defer the mrpc dma shutdown until way after devres_release_all, which unmapped stdev->mmio_mrpc. Also, stdev->pdev would be a stale pointer by then. Followed-up with a humble proposal how to fix it. Thanks, Daniel Daniel Stodden (1): switchtec: Fix stdev_release crash after suprise device loss. drivers/pci/switch/switchtec.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) -- 2.41.0