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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 96659C55179 for ; Sat, 31 Oct 2020 19:01:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5808D20791 for ; Sat, 31 Oct 2020 19:01:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604170891; bh=2kLF3qEgXyoiu7HPQnNsNJf4XpPEJLk24R5tLi6zJcc=; h=Date:From:To:Subject:List-ID:From; b=CJAwM+T/R7R1R3oQ5ywFrvWRo4QxS6cSYS5xSnmoL+N9AMZ4cEdbJb5KLuZFDRjC2 hCbVQElfcHXkkBsO1k/QL8cwXt3L1E6qGDNRQwt61hmj2pUMw+dJAORgRQH95QTiak GbaTUdbxQk9+Ch1e5NCCHBcbmeA/ZWfGLDwxwm3k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728432AbgJaTBa (ORCPT ); Sat, 31 Oct 2020 15:01:30 -0400 Received: from mail-wr1-f46.google.com ([209.85.221.46]:44374 "EHLO mail-wr1-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726627AbgJaTBa (ORCPT ); Sat, 31 Oct 2020 15:01:30 -0400 Received: by mail-wr1-f46.google.com with SMTP id b3so4092138wrx.11; Sat, 31 Oct 2020 12:01:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-disposition; bh=fo1vLw7uqzM0/HVmudKwwfC5LAehVsjoosFf5UWA8y0=; b=uAzRAJdvrzSFruVaBlWcp+QtmdOAo4cIHTy2W6P6A1PJTkgkizaIzzNYKnKg8+wbo7 Omchg07xbP/KJzAtjBmN0Kg9lLSYON0WUeqUjGBbc02Vs4im631BJlkN8IEENCKrXQzU hJjH/nQimpOade3cg7wSfJQaoMxc16vImF42xcI+2hrQ5Brgw2lh0uT1PG14IHnNOAET A0YTkd2YVVIma8D4pxTi0fXVggIMgUXZ/p5RUNE/GfFLrembKykis+gJI9tdTI7+OeJm X/KWWJFACSECoSkznafUF8oikmUyDSnwOD5ens7yVa+wDQh2y/fuDwSCcmUuCIsaL7za tCsA== X-Gm-Message-State: AOAM531Ypw7Xo2F+qTnvZjAk0sIuQ4xV5he17IsiZ9XbtKcUGOES1/YI VsJSyHZV9wwq2IxZeidJaAp4hgqzvccs+w== X-Google-Smtp-Source: ABdhPJxAoD+lJVSovF6LGZWjGAOGZSs5Ew9Xk7ScBo+AW4SrynsiHyTcb0Qsb6SAn5qAndIgOwcexg== X-Received: by 2002:adf:fc8b:: with SMTP id g11mr10785093wrr.300.1604170887339; Sat, 31 Oct 2020 12:01:27 -0700 (PDT) Received: from kozik-lap (adsl-84-226-167-205.adslplus.ch. [84.226.167.205]) by smtp.googlemail.com with ESMTPSA id e7sm15597705wrm.6.2020.10.31.12.01.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 31 Oct 2020 12:01:26 -0700 (PDT) Date: Sat, 31 Oct 2020 20:01:24 +0100 From: Krzysztof Kozlowski To: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, Marek Szyprowski , linux-samsung-soc@vger.kernel.org, Vinod Koul Subject: dmaengine: pl330 rare NULL pointer dereference in pl330_tasklet Message-ID: <20201031190124.GA486187@kozik-lap> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, I hit quite rare issue with pl330 DMA driver, difficult to reproduce (actually failed to do so): Happened during early reboot [ OK ] Stopped target Graphical Interface. [ OK ] Stopped target Multi-User System. [ OK ] Stopped target RPC Port Mapper. Stopping OpenSSH Daemonti[ 75.447904] 8<--- cut here --- [ 75.449506] Unable to handle kernel NULL pointer dereference at virtual address 0000000c ... [ 75.690850] [] (pl330_tasklet) from [] (tasklet_action_common+0x88/0x1f4) [ 75.699340] [] (tasklet_action_common) from [] (__do_softirq+0x108/0x428) [ 75.707850] [] (__do_softirq) from [] (run_ksoftirqd+0x2c/0x4c) [ 75.715486] [] (run_ksoftirqd) from [] (smpboot_thread_fn+0x13c/0x24c) [ 75.723693] [] (smpboot_thread_fn) from [] (kthread+0x13c/0x16c) [ 75.731390] [] (kthread) from [] (ret_from_fork+0x14/0x2c) Full log: https://krzk.eu/#/builders/20/builds/954/steps/22/logs/serial0 1. Arch ARM Linux 2. multi_v7_defconfig 3. Odroid HC1, ARMv7, octa-core (Cortex-A7+A15), Exynos5422 SoC 4. systemd, boot up with static IP set in kernel command line 5. No swap 6. Kernel, DTB and initramfs are downloaded with TFTP 7. NFS root (NFS client) mounted from a NFSv4 server Since I was not able to reproduce it, obviously I did not run bisect. If anyone has ideas, please share. Best regards, Krzysztof