From patchwork Mon Jan 24 18:46:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 535278 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 0E2C4C4707E for ; Mon, 24 Jan 2022 21:54:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1575237AbiAXVvK (ORCPT ); Mon, 24 Jan 2022 16:51:10 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:53240 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378618AbiAXVoA (ORCPT ); Mon, 24 Jan 2022 16:44:00 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 18B40B8123A; Mon, 24 Jan 2022 21:43:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A6C0C340E4; Mon, 24 Jan 2022 21:43:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643060637; bh=t36Qf7OqaHp5mhLh63Ejubt/7CRwFd48SoJJMeaqkEw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VwzbQcLF2W87QpR//XjxHNw7jM9G8kGeHB772m3LI9cB/0N8QSGfqipduRA1ncehP JAXxL1vRaPm2MFDw+tZz35gKUeSjdbT198exSxvM0YRjYSH2YFyjZCLIypjwi2Tmld gu3OxcuIgOzOsYiakuK7ULCGX+BBzdsWiUAkTPao= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Laurence de Bruxelles , Alexandre Belloni Subject: [PATCH 5.16 0981/1039] rtc: pxa: fix null pointer dereference Date: Mon, 24 Jan 2022 19:46:10 +0100 Message-Id: <20220124184158.258239040@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184125.121143506@linuxfoundation.org> References: <20220124184125.121143506@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Laurence de Bruxelles commit 34127b3632b21e5c391756e724b1198eb9917981 upstream. With the latest stable kernel versions the rtc on the PXA based Zaurus does not work, when booting I see the following kernel messages: pxa-rtc pxa-rtc: failed to find rtc clock source pxa-rtc pxa-rtc: Unable to init SA1100 RTC sub-device pxa-rtc: probe of pxa-rtc failed with error -2 hctosys: unable to open rtc device (rtc0) I think this is because commit f2997775b111 ("rtc: sa1100: fix possible race condition") moved the allocation of the rtc_device struct out of sa1100_rtc_init and into sa1100_rtc_probe. This means that pxa_rtc_probe also needs to do allocation for the rtc_device struct, otherwise sa1100_rtc_init will try to dereference a null pointer. This patch adds that allocation by copying how sa1100_rtc_probe in drivers/rtc/rtc-sa1100.c does it; after the IRQs are set up a managed rtc_device is allocated. I've tested this patch with `qemu-system-arm -machine akita` and with a real Zaurus SL-C1000 applied to 4.19, 5.4, and 5.10. Signed-off-by: Laurence de Bruxelles Fixes: f2997775b111 ("rtc: sa1100: fix possible race condition") Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20220101154149.12026-1-lfdebrux@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-pxa.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/rtc/rtc-pxa.c +++ b/drivers/rtc/rtc-pxa.c @@ -330,6 +330,10 @@ static int __init pxa_rtc_probe(struct p if (sa1100_rtc->irq_alarm < 0) return -ENXIO; + sa1100_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(sa1100_rtc->rtc)) + return PTR_ERR(sa1100_rtc->rtc); + pxa_rtc->base = devm_ioremap(dev, pxa_rtc->ress->start, resource_size(pxa_rtc->ress)); if (!pxa_rtc->base) {