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imf05.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf05.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=liushixin2@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1675414611; a=rsa-sha256; cv=none; b=3sMNl1bayM3XNAgWtmZU036uD2kRwulH0TJ1hP1snw5jIiP+tgBLENkpi/dXjy8dT2zFiP HiKkNRavI3vgvjzXKtdQGU8S6mWkyM5W9tqCcFcjOQv3G7eHTGRX+T1mEgIs8ecwOzBN37 iPUM+osn6y/w2dSe9A2E0MzE+MuyvRU= Received: from dggpemm100009.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4P7TzN5blxzfZ4D; Fri, 3 Feb 2023 16:56:32 +0800 (CST) Received: from [10.174.179.24] (10.174.179.24) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Fri, 3 Feb 2023 16:56:44 +0800 Subject: Re: [PATCH RFC] arm64/vmalloc: use module region only for module_alloc() if CONFIG_RANDOMIZE_BASE is set To: Ard Biesheuvel , Will Deacon References: <20221227092634.445212-1-liushixin2@huawei.com> <20230129134147.f19ca0641f1133f3e3bc185b@linux-foundation.org> <20230131150644.GA2605@willie-the-truck> <20230131150750.GB2605@willie-the-truck> CC: Andrew Morton , Catalin Marinas , Uladzislau Rezki , Christoph Hellwig , , , From: Liu Shixin Message-ID: <5ecc890a-453a-ba2d-9c5e-073127067799@huawei.com> Date: Fri, 3 Feb 2023 16:56:43 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.179.24] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 97F5E10000E X-Stat-Signature: xonpim7w4pnn1gbiq5nrz4qnr1crfsoy X-HE-Tag: 1675414609-720516 X-HE-Meta: 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 wIZE7keX RfGgucbiUy4weUYun5Irzt8xwFPr6h4j60KPCGHKZcEo8ZkMTZURe2Mj+NqpeuyLwYVA0qHaq4E18Wmczb1aGQGqpCdhlJWZdviWJB4cA6BYFGDgd+Vroy5NaJpky7i7tFSOkk531RZs1HDGYUPrAu4k7YOZaP0sWZjgw+s7YN10MGhRrkuWp2Iy6snG49Yy0nHPPwmvBguJExQD87zRTxqizpTF8c2rf705kYfdTZzC6EV4tEOcN4XRp/yDLNAOMcG4SYskr+U/vtVEcvESfWOBXkSwhzmOef6GL/U/9QilVcDnhVXVmXqstQ1TtDjlu8mNaw2I31zIhdbfQfFxc2J2i8Z0AyFYX4OmDpXPARX9SZY4Mv4vZ7OEFLhyzPCeMG+/f48X+A30AP2yq+2v32w16B0zdSzNlik6xHaqViuP9D3o= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2023/2/1 0:03, Ard Biesheuvel wrote: > On Tue, 31 Jan 2023 at 16:07, Will Deacon wrote: >> Now really adding Ard... >> >> On Tue, Jan 31, 2023 at 03:06:44PM +0000, Will Deacon wrote: >>> +Ard -- full thread here: >>> >>> https://lore.kernel.org/all/20221227092634.445212-1-liushixin2@huawei.com/ >>> >>> On Sun, Jan 29, 2023 at 01:41:47PM -0800, Andrew Morton wrote: >>>> On Sun, 29 Jan 2023 10:44:31 +0800 Liu Shixin wrote: >>>> >>>>> Hi, >>>>> >>>>> >>>>> This patch seems to have been lost in the corner. Recently I've meet this problem again >>>>> >>>>> on v6.1, so I would like to propose this patch again. >>>>> >>>>> >>>>> Thanks, >>>>> >>>>> >>>>> On 2022/12/27 17:26, Liu Shixin wrote: >>>>>> After I add a 10GB pmem device, I got the following error message when >>>>>> insert module: >>>>>> >>>>>> insmod: vmalloc error: size 16384, vm_struct allocation failed, >>>>>> mode:0xcc0(GFP_KERNEL), nodemask=(null),cpuset=/,mems_allowed=0 >>>>>> >>>>>> If CONFIG_RANDOMIZE_BASE is set, the module region can be located in the >>>>>> vmalloc region entirely. Although module_alloc() can fall back to a 2GB >>>>>> window if ARM64_MODULE_PLTS is set, the module region is still easily >>>>>> exhausted because the module region is located at bottom of vmalloc region >>>>>> and the vmalloc region is allocated from bottom to top. >>>>>> >>>>>> Skip module region if not calling from module_alloc(). >>>>>> >>>> I'll assume this is for the arm tree. >>>> >>>> Acked-by: Andrew Morton >>> This looks like the same issue previously reported at: >>> >>> https://lore.kernel.org/all/e6a804de-a5f7-c551-ffba-e09d04e438fc@hisilicon.com/ >>> >>> where Ard had a few suggestions but, afaict, they didn't help. >>> > Thanks for the cc. > > So this is a bit clunky, and I wonder whether we wouldn't be better > off just splitting the vmalloc region into two separate regions: one > for the kernel and modules, and one for everything else. That way, we > lose one bit of entropy in the randomized placement, but the default > 48-bit VA space is vast anway, and even on 39-bit VA configs (such as > Android), I seriously doubt that we come anywhere close to exhausting > the vmalloc space today. > . Thanks for your advice. >