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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 CDF50C433DB for ; Sun, 10 Jan 2021 11:36:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FE19238E9 for ; Sun, 10 Jan 2021 11:36:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726390AbhAJLgR convert rfc822-to-8bit (ORCPT ); Sun, 10 Jan 2021 06:36:17 -0500 Received: from aposti.net ([89.234.176.197]:33724 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726069AbhAJLgQ (ORCPT ); Sun, 10 Jan 2021 06:36:16 -0500 Date: Sun, 10 Jan 2021 11:35:01 +0000 From: Paul Cercueil Subject: Re: [patch V3 13/37] mips/mm/highmem: Switch to generic kmap atomic To: Thomas Bogendoerfer Cc: tglx@linutronix.de, airlied@linux.ie, airlied@redhat.com, akpm@linux-foundation.org, arnd@arndb.de, bcrl@kvack.org, bigeasy@linutronix.de, bristot@redhat.com, bsegall@google.com, bskeggs@redhat.com, chris@zankel.net, christian.koenig@amd.com, clm@fb.com, davem@davemloft.net, deanbo422@gmail.com, dietmar.eggemann@arm.com, dri-devel@lists.freedesktop.org, dsterba@suse.com, green.hu@gmail.com, hch@lst.de, intel-gfx@lists.freedesktop.org, jcmvbkbc@gmail.com, josef@toxicpanda.com, juri.lelli@redhat.com, kraxel@redhat.com, linux-aio@kvack.org, linux-arm-kernel@lists.infradead.org, linux-btrfs@vger.kernel.org, linux-csky@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-graphics-maintainer@vmware.com, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, linux@armlinux.org.uk, linuxppc-dev@lists.ozlabs.org, mgorman@suse.de, mingo@kernel.org, monstr@monstr.eu, mpe@ellerman.id.au, nickhu@andestech.com, nouveau@lists.freedesktop.org, paulmck@kernel.org, paulus@samba.org, peterz@infradead.org, ray.huang@amd.com, rodrigo.vivi@intel.com, rostedt@goodmis.org, sparclinux@vger.kernel.org, spice-devel@lists.freedesktop.org, sroland@vmware.com, torvalds@linuxfoundation.org, vgupta@synopsys.com, vincent.guittot@linaro.org, viro@zeniv.linux.org.uk, virtualization@lists.linux-foundation.org, x86@kernel.org Message-Id: In-Reply-To: <20210109003352.GA18102@alpha.franken.de> References: <20210108235805.GA17543@alpha.franken.de> <20210109003352.GA18102@alpha.franken.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, Le sam. 9 janv. 2021 à 1:33, Thomas Bogendoerfer a écrit : > On Sat, Jan 09, 2021 at 12:58:05AM +0100, Thomas Bogendoerfer wrote: >> On Fri, Jan 08, 2021 at 08:20:43PM +0000, Paul Cercueil wrote: >> > Hi Thomas, >> > >> > 5.11 does not boot anymore on Ingenic SoCs, I bisected it to this >> commit. >> > >> > Any idea what could be happening? >> >> not yet, kernel crash log of a Malta QEMU is below. > > update: > > This dirty hack lets the Malta QEMU boot again: > > diff --git a/mm/highmem.c b/mm/highmem.c > index c3a9ea7875ef..190cdda1149d 100644 > --- a/mm/highmem.c > +++ b/mm/highmem.c > @@ -515,7 +515,7 @@ void *__kmap_local_pfn_prot(unsigned long pfn, > pgprot_t prot) > vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); > BUG_ON(!pte_none(*(kmap_pte - idx))); > pteval = pfn_pte(pfn, prot); > - set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval); > + set_pte(kmap_pte - idx, pteval); > arch_kmap_local_post_map(vaddr, pteval); > current->kmap_ctrl.pteval[kmap_local_idx()] = pteval; > preempt_enable(); > > set_pte_at() tries to update cache and could do an kmap_atomic() > there. > Not sure, if this is allowed at this point. Yes, I can confirm that your workaround works here too. Cheers, -Paul