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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 700E4C4338F for ; Sun, 1 Aug 2021 15:23:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E068610A5 for ; Sun, 1 Aug 2021 15:23:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232168AbhHAPXZ (ORCPT ); Sun, 1 Aug 2021 11:23:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:47866 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231940AbhHAPXZ (ORCPT ); Sun, 1 Aug 2021 11:23:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 666C560243; Sun, 1 Aug 2021 15:23:15 +0000 (UTC) Date: Sun, 1 Aug 2021 08:23:12 -0700 From: Catalin Marinas To: Kefeng Wang Cc: Will Deacon , Andrey Ryabinin , Andrey Konovalov , Dmitry Vyukov , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org Subject: Re: [PATCH v2 1/3] vmalloc: Choose a better start address in vm_area_register_early() Message-ID: <20210801152311.GB28489@arm.com> References: <20210720025105.103680-1-wangkefeng.wang@huawei.com> <20210720025105.103680-2-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210720025105.103680-2-wangkefeng.wang@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 20, 2021 at 10:51:03AM +0800, Kefeng Wang wrote: > There are some fixed locations in the vmalloc area be reserved > in ARM(see iotable_init()) and ARM64(see map_kernel()), but for > pcpu_page_first_chunk(), it calls vm_area_register_early() and > choose VMALLOC_START as the start address of vmap area which > could be conflicted with above address, then could trigger a > BUG_ON in vm_area_add_early(). > > Let's choose the end of existing address range in vmlist as the > start address instead of VMALLOC_START to avoid the BUG_ON. > > Signed-off-by: Kefeng Wang > --- > mm/vmalloc.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index d5cd52805149..a98cf97f032f 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2238,12 +2238,14 @@ void __init vm_area_add_early(struct vm_struct *vm) > */ > void __init vm_area_register_early(struct vm_struct *vm, size_t align) > { > - static size_t vm_init_off __initdata; > + unsigned long vm_start = VMALLOC_START; > + struct vm_struct *tmp; > unsigned long addr; > > - addr = ALIGN(VMALLOC_START + vm_init_off, align); > - vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; > + for (tmp = vmlist; tmp; tmp = tmp->next) > + vm_start = (unsigned long)tmp->addr + tmp->size; > > + addr = ALIGN(vm_start, align); > vm->addr = (void *)addr; > > vm_area_add_early(vm); Is there a risk of breaking other architectures? It doesn't look like to me but I thought I'd ask. Also, instead of always picking the end, could we search for a range that fits? -- Catalin