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 0EB52EB64DA for ; Sat, 15 Jul 2023 02:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229900AbjGOCjU (ORCPT ); Fri, 14 Jul 2023 22:39:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229796AbjGOCjT (ORCPT ); Fri, 14 Jul 2023 22:39:19 -0400 Received: from mailgw.gate-on.net (auth.gate-on.net [IPv6:2001:278:1033:4::74:21]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51805359F for ; Fri, 14 Jul 2023 19:39:17 -0700 (PDT) Received: from vega.pgw.jp (unknown [49.135.109.134]) by mailgw.gate-on.net (Postfix) with ESMTP id 813E68018A; Sat, 15 Jul 2023 11:39:14 +0900 (JST) Received: from localhost (vega.pgw.jp [10.5.0.30]) by vega.pgw.jp (Postfix) with SMTP id 3562DA53D; Sat, 15 Jul 2023 11:39:11 +0900 (JST) From: Content-Type: text/plain; charset=ISO-2022-JP To: rostedt@goodmis.org Cc: kkabe@vega.pgw.jp, regressions@lists.linux.dev, bagasdotme@gmail.com, alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org Subject: Re: radeon.ko/i586: BUG: kernel NULL pointer dereference,address:00000004 In-Reply-To: Your message of "Fri, 14 Jul 2023 10:00:19 -0400". <20230714100019.6bf9b1ab@gandalf.local.home> X-Mailer: mnews [version 1.22PL5] 2002-11-27(Wed) Date: Sat, 15 Jul 2023 11:39:11 +0900 Message-ID: <230715113911.M0124687@vega.pgw.jp> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org rostedt@goodmis.org sed in <20230714100019.6bf9b1ab@gandalf.local.home> >> On Fri, 14 Jul 2023 14:34:04 +0900 >> wrote: >> >> > >> > So I'm confused about why it's mentioned. Was it backported? >> > >> >> > >> Taketo Kabe, could you please help to clean this confusion up? Did you >> > >> mean 5.19 in https://bugzilla.kernel.org/show_bug.cgi?id=217669#c5 ? And >> > >> BTW: did you really use a vanilla kernel for your bisection? >> > >> > >> > Reporter Me: >> > I bisected using freedesktop.org kernel tree, which git commit ID is >> > in sync with kernel.org >> > but version number in ./Makefile could be slighty behind. >> > >> > Patch in >> > https://bugzilla.kernel.org/show_bug.cgi?id=217669#c4 >> > fixed the problem in freedesktop.org kernel 5.18.0-rc2 . >> > This may explain that in kernel.org tree, the said commit is in kernel-5.19. >> >> Even if the bisect did land on this commit, it doesn't make sense. I would >> think that one of the results of the bisect was incorrect (a pass that >> should have failed?), as that would lead the bisect down to the wrong >> conclusion. >> >> Now if you you remove this commit and everything works fine, and add it >> back again and it fails reliably, then I can't argue it is not the commit. I agree with that it does not make sense. But reverting that commit made the freedesktop.org kernel-5.18-0-rc2 not panic, and adding it back made kernel panic (actually, check for vblank->worker==NULL fires) >> >> But the commit in question kicks off a worker thread at boot up to search >> for weak functions that were tagged to be traced by the function tracer and >> sets them to "disabled" to never be traced. >> >> Is the function tracer used at all here? I really do not see how this >> commit affects the code that is crashing. Unless there's something wrong >> with the way the kworker was set up and it corrupted other kworkers :-/ >> -- Steve Yes, this is puzzling. That's why I need other people's opinion on this. Does it matter the DUT is a slow machine (Pentium 120MHz)? -- kabe