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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E495BC4332F for ; Tue, 13 Dec 2022 23:05:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236875AbiLMXFo (ORCPT ); Tue, 13 Dec 2022 18:05:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236149AbiLMXFm (ORCPT ); Tue, 13 Dec 2022 18:05:42 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51743127 for ; Tue, 13 Dec 2022 15:05:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description; bh=acFcWsZp8jeuy0aOVlX6PCUPzovLJAhrsBv6ucRF3IU=; b=gi8Qn5HRZAtpxzz5YJZ05RPV8g YJ0W7ei0he98EPBkc/C6n9oP+SGGHW+OZVWGoDeSShO4KHZT2AMnaQGFrSeufGjh0TMzW7OeZEmlx prUxCXndMK79i6OS38dDpWijDBvTEugkcuqkxM7zKHdeAdcbvXqWI6RMl1ZnpWjtaoeniR3PK3BOf alnuEcmqJvhsipsytjf+H789Pr92NPi7NisZUkwxUcfURmBiNECXXiSoM+LS1SeDOAPqK20b6LAVd 5Wm4OJytRw3tuF3cXJGoWoSLN9AhKtUi7v97bpioc85HlplK4pBzlUZ5n7K621alFIgYY2H+/p4XF Rb9du+fw==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1p5ELD-0084r9-L8; Tue, 13 Dec 2022 23:05:39 +0000 Date: Tue, 13 Dec 2022 15:05:39 -0800 From: Luis Chamberlain To: =?utf-8?Q?Micha=C5=82?= Lach Cc: linux-kernel@vger.kernel.org, russell.h.weight@intel.com, gregkh@linuxfoundation.org, rafael@kernel.org, tiwai@suse.de Subject: Re: [PATCH] drivers/firmware_loader: remove list entry before deallocation Message-ID: References: <20221123111455.94972-1-michal.lach@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 12, 2022 at 06:52:51PM +0100, Michał Lach wrote: > On 12/12/22 07:04, Luis Chamberlain wrote: > > Hey Michal! Thanks for your patch! I have a few doubts though! > > :-) > > > To account for not having to deal with specific drivers we have the > > Linux kernel selftests. And so you can test the firmware loader with all > > sorts of crazy situations which any driver could use and try to see > > if you can re-recreate the issue. > > > > The kernel selftests driver for the firmware loader is in > > lib/test_firmware.c and you can use thetools/testing/selftests/firmware/fw_run_tests.sh > > to run all the tests. To test the firmware fallback alone you can use > > just fw_fallback.sh. > > > > If you want to just virtualize this and you can also use kdevops [0] and > > enable the firmware loader selftest and use:; > > > > make menuconfig # enable selftests and just the firmware test > > make linux # build linux, pick linux-next > > make selftests > > make selftests-firmware > > > > But this may be something more you can use later once you get your flow > > going. Just compiling the kernel and running the selftest manually with > > fw_fallback.sh should suffice. > > Thanks a lot, I had no idea that there is something like this. selftests has been there for ages, kdevops support for selftests is pretty new, like 1 week old only :) > > OK so this proves the bug can happen but I'd like to see the full trace > > and the exact kernel version showing that this can happen on a recent > > kernel. Without that I'm not seeing how this can trigger yet. > > Unfortunately I cannot provide a trace. The kernel version was 5.15.41 (-stable). Ah, I suspected as much, given I couldn't see how this could happen in linux-next. > Keeping that in mind, I will try to reproduce this behaviour with in-tree > code and provide proof. Yes please use linux-next, if you can't reproduce there then likely your kernel is missing some fixes. Luis