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 E96E9C433EF for ; Thu, 9 Jun 2022 10:26:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242235AbiFIK0I (ORCPT ); Thu, 9 Jun 2022 06:26:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233741AbiFIK0G (ORCPT ); Thu, 9 Jun 2022 06:26:06 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CFFD312D140; Thu, 9 Jun 2022 03:26:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8D46BB82C86; Thu, 9 Jun 2022 10:26:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D37CC34114; Thu, 9 Jun 2022 10:25:58 +0000 (UTC) Date: Thu, 9 Jun 2022 11:25:55 +0100 From: Catalin Marinas To: Will Deacon Cc: Kefeng Wang , Vasily Averin , Naresh Kamboju , Shakeel Butt , Linux ARM , Stephen Rothwell , Linux-Next Mailing List , open list , regressions@lists.linux.dev, lkft-triage@lists.linaro.org, linux-mm , Andrew Morton , Ard Biesheuvel , Arnd Bergmann , Raghuram Thammiraju , Mark Brown , Roman Gushchin , Qian Cai Subject: Re: [next] arm64: boot failed - next-20220606 Message-ID: References: <20220607162504.7fd5a92a@canb.auug.org.au> <2a4cc632-c936-1e42-4fdc-572334c58ee1@openvz.org> <44530040-0384-796e-143f-b7293886753c@huawei.com> <20220609101153.GB2187@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220609101153.GB2187@willie-the-truck> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 09, 2022 at 11:11:54AM +0100, Will Deacon wrote: > On Thu, Jun 09, 2022 at 11:44:09AM +0800, Kefeng Wang wrote: > > On 2022/6/9 10:49, Vasily Averin wrote: > > > mem_cgroup_from_obj(): > > > ffff80000836cf40: d503245f bti c > > > ffff80000836cf44: d503201f nop > > > ffff80000836cf48: d503201f nop > > > ffff80000836cf4c: d503233f paciasp > > > ffff80000836cf50: d503201f nop > > > ffff80000836cf54: d2e00021 mov x1, #0x1000000000000 // #281474976710656 > > > ffff80000836cf58: 8b010001 add x1, x0, x1 > > > ffff80000836cf5c: b25657e4 mov x4, #0xfffffc0000000000 // #-4398046511104 > > > ffff80000836cf60: d34cfc21 lsr x1, x1, #12 > > > ffff80000836cf64: d37ae421 lsl x1, x1, #6 > > > ffff80000836cf68: 8b040022 add x2, x1, x4 > > > ffff80000836cf6c: f9400443 ldr x3, [x2, #8] > > > > > > x5 : ffff80000a96f000 x4 : fffffc0000000000 x3 : ffff80000ad5e680 > > > x2 : fffffe00002bc240 x1 : 00000200002bc240 x0 : ffff80000af09740 > > > > > > x0 = 0xffff80000af09740 is an argument of mem_cgroup_from_obj() > > > according to System.map it is init_net > > > > > > This issue is caused by calling virt_to_page() on address of static variable init_net. > > > Arm64 consider that addresses of static variables are not valid virtual addresses. > > > On x86_64 the same API works without any problem. > > This just depends on whether or not the kernel is running out of the linear > mapping or not. On arm64, we use the vmalloc area for the kernel image and > so virt_to_page() won't work, just like it won't work for modules on other > architectures. > > How are module addresses handled by mem_cgroup_from_obj()? It doesn't look like they are handled in any way. It just expects the pointer to be a linear map one. Something like below: diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 27cebaa53472..795bf3673fa7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2860,6 +2860,11 @@ struct mem_cgroup *mem_cgroup_from_obj(void *p) if (mem_cgroup_disabled()) return NULL; + if (is_module_address((unsigned long)p)) + return NULL; + else if (is_kernel((unsigned long)p)) + return NULL; + folio = virt_to_folio(p); /* -- Catalin