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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham 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 BD450C43142 for ; Fri, 22 Jun 2018 18:31:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A71E24737 for ; Fri, 22 Jun 2018 18:31:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XZGVo17N" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A71E24737 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934328AbeFVSbT (ORCPT ); Fri, 22 Jun 2018 14:31:19 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:40587 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933869AbeFVSbR (ORCPT ); Fri, 22 Jun 2018 14:31:17 -0400 Received: by mail-pf0-f195.google.com with SMTP id z24-v6so3594493pfe.7; Fri, 22 Jun 2018 11:31:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Dnlmeh0ETRyTeQmQmJpCWaYnEVSEN/4h7gHXw6oj92o=; b=XZGVo17NoLaFqAfuKkuTDWfQhoF/O6wM5fndQLT2HlHWP26x2HTVUOlKonsPA6teZi vQI2aIzVeVMegWKww5aUEU81iom64CVwEgMHCY1AN+055kWK1MMkKzE75WJYxmXQk0QT I5OS8ZQZ/G3nqGs1auXk4Pi5f9e3/r3+VW78BV421Q49CyBFSLItwb7TwdXzOWRmlzaZ tO7NPe7SOOzeqhFL4YknY5wdoRjvbWbg1fDzmz4U6Pvh//Rwg+FJNidbcRNnx51JCfD/ X4x8p2yG+k06PjxfEMmOQagZW0PJPQ9MCIFtF6bk04iQRRZKxexLJICB8KgD7MdtoRmj kSyg== 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:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=Dnlmeh0ETRyTeQmQmJpCWaYnEVSEN/4h7gHXw6oj92o=; b=nQymIxNy7cH3xcAit6iw0kdX3BQtNU3Zg8PnPSExqkGEYAtUOftnRopCdulwF561hA df5Q9Y88ihEn1NVi6HrZvJdTQFCmxzjlUU7LUuEG4rGNZVDauQiTv/otXvX/g8gHI1NH /cDhdqehrYVJUTSxk7xl2hoTSZ8MNTY1lTE0LrRS27WkJHW7oUepL99gF6BQ2V0AEFHv 4q/Ig9og4h0vMWGmOV1xATtpmr3UHWbdY8QAvX9Acilj+uNCbcF62FuQUogM3eEtfG0r j4t4j/XOpHIM48vCLYdRzm3LMbm1PT1sEWxZQzeOR+MZm0qkqHOzjSfEPJCNNDgcY7fw aPAg== X-Gm-Message-State: APt69E3l4IGtsg2zCf+WzaqVuW0913ltcInsCuZamLDEJx9RIr57RbQK 6VI+Z25OMu8zHDsCZ7KD4DyGsevd X-Google-Smtp-Source: ADUXVKLWK6fSB6VMB8pTJvG0eYbXanKfPHbMESmANTrhEuzzu59X1diupblMBtkjjpjKbXCwuyDp4Q== X-Received: by 2002:a63:7d4c:: with SMTP id m12-v6mr2361286pgn.201.1529692277076; Fri, 22 Jun 2018 11:31:17 -0700 (PDT) Received: from dtor-ws ([2620:0:1000:1511:8de6:27a8:ed13:2ef5]) by smtp.gmail.com with ESMTPSA id r3-v6sm4380740pfl.162.2018.06.22.11.31.15 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 22 Jun 2018 11:31:16 -0700 (PDT) Date: Fri, 22 Jun 2018 11:31:14 -0700 From: Dmitry Torokhov To: Matthias Brugger Cc: chen.zhong@mediatek.com, lee.jones@linaro.org, linux-input@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, Matthias Brugger Subject: Re: [PATCH] input: mtk-pmic-keys: Fix probe when no DT node present Message-ID: <20180622183114.GA92912@dtor-ws> References: <20180622114228.8619-1-matthias.bgg@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180622114228.8619-1-matthias.bgg@gmail.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 22, 2018 at 01:42:28PM +0200, Matthias Brugger wrote: > The drivers gets probed from a mfd devices. So the driver runs > probe although no DT node exists. This leads to a NULL pointer > dereference in the probe function. Check if a node exists and > error out in case none is present. Hmm, if a cell specifies of_compatible and no such node is present in DT maybe we should bail out in mfd_add_device() instead of pushing the check into individual drivers? Something like: diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index 94e3f32ce935..36a5fd98000d 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -137,6 +137,18 @@ static inline void mfd_acpi_add_device(const struct mfd_cell *cell, } #endif +static struct device_node *mfd_get_node_for_cell(struct device *parent, + const struct mfd_cell *cell) +{ + struct device_node *np; + + for_each_child_of_node(parent->of_node, np) + if (of_device_is_compatible(np, cell->of_compatible)) + return np; + + return NULL; +} + static int mfd_add_device(struct device *parent, int id, const struct mfd_cell *cell, atomic_t *usage_count, struct resource *mem_base, @@ -144,7 +156,6 @@ static int mfd_add_device(struct device *parent, int id, { struct resource *res; struct platform_device *pdev; - struct device_node *np = NULL; int ret = -ENOMEM; int platform_id; int r; @@ -176,11 +187,11 @@ static int mfd_add_device(struct device *parent, int id, goto fail_res; if (parent->of_node && cell->of_compatible) { - for_each_child_of_node(parent->of_node, np) { - if (of_device_is_compatible(np, cell->of_compatible)) { - pdev->dev.of_node = np; - break; - } + pdev->dev.of_node = mfd_get_node_for_cell(parent, cell); + if (!pdev->dev.of_node) { + dev_err(parent, "unable to locate node for %s (%s)\n", + cell->name, cell->of_compatible); + goto fail_res; } } Lee? > > Fixes: 3e9f0b3e2b27 ("input: Add MediaTek PMIC keys support") > Signed-off-by: Matthias Brugger > --- > drivers/input/keyboard/mtk-pmic-keys.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/input/keyboard/mtk-pmic-keys.c b/drivers/input/keyboard/mtk-pmic-keys.c > index 02c67a1749fc..388043e1939c 100644 > --- a/drivers/input/keyboard/mtk-pmic-keys.c > +++ b/drivers/input/keyboard/mtk-pmic-keys.c > @@ -257,6 +257,9 @@ static int mtk_pmic_keys_probe(struct platform_device *pdev) > const struct of_device_id *of_id = > of_match_device(of_mtk_pmic_keys_match_tbl, &pdev->dev); > > + if (of_id == NULL) > + return -ENODEV; > + > keys = devm_kzalloc(&pdev->dev, sizeof(*keys), GFP_KERNEL); > if (!keys) > return -ENOMEM; > -- > 2.17.1 > Thanks. -- Dmitry