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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 F1FDFC433B4 for ; Wed, 28 Apr 2021 14:14:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B752D61442 for ; Wed, 28 Apr 2021 14:14:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229807AbhD1OOw (ORCPT ); Wed, 28 Apr 2021 10:14:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:49592 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229961AbhD1OOs (ORCPT ); Wed, 28 Apr 2021 10:14:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D74EE61424; Wed, 28 Apr 2021 14:14:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1619619243; bh=LrI9EyriTNzlF19LSDUJcI9lL1R/vtRwbqVxLduTtIA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aUuQDDlV5/Weo5NpINpcpgbKVC3oTwegSq+1ZGp+9bav91ppzXIUL+jJKMZQvI7ZC LEmcSQBcyP6vQ6HR3cUREPha/3TQTiqyb4Y1qNlrsjq7MX35xc1XxySN1EI5DH35Lm VLXt+35DsqVRNuu0+mumLlWuIIHBDHsRUpaae9x8= Date: Wed, 28 Apr 2021 16:14:00 +0200 From: Greg Kroah-Hartman To: Dmitry Torokhov Cc: linux-kernel@vger.kernel.org, Aditya Pakki Subject: Re: [PATCH 157/190] Revert "Input: ad7879 - add check for read errors in interrupt" Message-ID: References: <20210421130105.1226686-1-gregkh@linuxfoundation.org> <20210421130105.1226686-158-gregkh@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 27, 2021 at 12:22:12PM -0700, Dmitry Torokhov wrote: > On Tue, Apr 27, 2021 at 06:55:10PM +0200, Greg Kroah-Hartman wrote: > > On Wed, Apr 21, 2021 at 10:03:33AM -0700, Dmitry Torokhov wrote: > > > Hi Greg, > > > > > > On Wed, Apr 21, 2021 at 03:00:32PM +0200, Greg Kroah-Hartman wrote: > > > > This reverts commit e85bb0beb6498c0dffe18a2f1f16d575bc175c32. > > > > > > > > Commits from @umn.edu addresses have been found to be submitted in "bad > > > > faith" to try to test the kernel community's ability to review "known > > > > malicious" changes. The result of these submissions can be found in a > > > > paper published at the 42nd IEEE Symposium on Security and Privacy > > > > entitled, "Open Source Insecurity: Stealthily Introducing > > > > Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University > > > > of Minnesota) and Kangjie Lu (University of Minnesota). > > > > > > > > Because of this, all submissions from this group must be reverted from > > > > the kernel tree and will need to be re-reviewed again to determine if > > > > they actually are a valid fix. Until that work is complete, remove this > > > > change to ensure that no problems are being introduced into the > > > > codebase. > > > > > > This one looks really OK to me and does not have to be reverted (unless > > > Aditya will come clean and show the error introduced?). > > > > I'll drop this revert, but it isn't usually good to be calling printk() > > from an irq. > > How else do you suggest we tell that something is wrong when > communicating with the device? For these types of devices the > communication is essentially unsolicited so we can't pass failure to a > caller to deal with it (i.e. unlike USB there is no URB posted that we > could fail and use as a mechanism to signal error to some other layer) > and while we could invent "something went wrong" input event so far > there was no interest in having anything like that. > > I'd suggest sending KOBJ_ERROR uevent when a device driver detects > anomaly in the device it controls, but I wonder how systemd would react > given past experiences with KOBJ_BIND/KOBJ_UNBIND. > > The message is ratelimited so it will not overfill the logs... Sending uevents from an irq is not a good idea, as you say :) I don't know what the best way to "fail" this is, a ratelimited printk() seems to be about all you can do. Luckily hardware doesn't fail that often in this manner. thanks, greg k-h