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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 0ABDAC282C4 for ; Mon, 4 Feb 2019 11:00:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCCEE2073D for ; Mon, 4 Feb 2019 11:00:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549278007; bh=CFZBMG+UMSpSZ7og1sgnVHrbmoTGb2VEDx2BhAyRM4k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=doDN1jf2I/hlHRJne9n9Q2QcfjQHvojoKJ5zcQpq/FBjhX1d72xotDOywJY46rq4p OOQbSAKXskjR0xtiuWUIVA2NgElTLGgmTqIKkSfCGzip9TbGdN5vYTK1/ngkBOcTSQ cu5RKM1g3jxd8b1T2fCuwO8dKY71ltr5iFFZX7w8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732746AbfBDLAG (ORCPT ); Mon, 4 Feb 2019 06:00:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:47304 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731610AbfBDKt2 (ORCPT ); Mon, 4 Feb 2019 05:49:28 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9B86F2070C; Mon, 4 Feb 2019 10:49:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277368; bh=CFZBMG+UMSpSZ7og1sgnVHrbmoTGb2VEDx2BhAyRM4k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RUrBNc+KaVcew+Jvmi+dTgImh1MTug3Z6gFJEdzZMffLfaJ/7kj5H2hk8mtifuzCX Wf6Ij+4TOLEnsEqjmzOuWaxWtJiI+xMHr+j/jbwNqgDbSDjXNLk3jHZLV8G2b6MvDX Fbnt60DNShP5iAIx4+dh+i1xdLQnc1qlLSFmcf0c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bartosz Golaszewski Subject: [PATCH 4.19 46/74] gpiolib: fix line event timestamps for nested irqs Date: Mon, 4 Feb 2019 11:36:59 +0100 Message-Id: <20190204103625.524388736@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190204103619.714714157@linuxfoundation.org> References: <20190204103619.714714157@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bartosz Golaszewski commit 1033be58992f818dc564196ded2bcc3f360bc297 upstream. Nested interrupts run inside the calling thread's context and the top half handler is never called which means that we never read the timestamp. This issue came up when trying to read line events from a gpiochip using regmap_irq_chip for interrupts. Fix it by reading the timestamp from the irq thread function if it's still 0 by the time the second handler is called. Fixes: d58f2bf261fd ("gpio: Timestamp events in hardirq handler") Cc: stable@vger.kernel.org Signed-off-by: Bartosz Golaszewski Signed-off-by: Greg Kroah-Hartman --- drivers/gpio/gpiolib.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -817,7 +817,15 @@ static irqreturn_t lineevent_irq_thread( /* Do not leak kernel stack to userspace */ memset(&ge, 0, sizeof(ge)); - ge.timestamp = le->timestamp; + /* + * We may be running from a nested threaded interrupt in which case + * we didn't get the timestamp from lineevent_irq_handler(). + */ + if (!le->timestamp) + ge.timestamp = ktime_get_real_ns(); + else + ge.timestamp = le->timestamp; + level = gpiod_get_value_cansleep(le->desc); if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE