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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 BE6CBC43441 for ; Thu, 29 Nov 2018 01:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 709222086B for ; Thu, 29 Nov 2018 01:41:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="hP5fxc6+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 709222086B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727303AbeK2Moo (ORCPT ); Thu, 29 Nov 2018 07:44:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:60412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727207AbeK2Moo (ORCPT ); Thu, 29 Nov 2018 07:44:44 -0500 Received: from mail-wm1-f43.google.com (mail-wm1-f43.google.com [209.85.128.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 97CD321473 for ; Thu, 29 Nov 2018 01:41:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543455666; bh=QxY/NrOLFMD1bey0Bu9s7XYJ30r/UjceZG582NRQnQA=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=hP5fxc6+ml4dzqJ2jPzkXojP8oMLxzNzLlyfU1EpJRSoWXFI0PGI1xJ/FwAL1xjhK 6wu/lwVNisjBUkeoKM2pKjFa+ZNpoYU0bXgNepFFgeTBTEdnXd66sdSF3YUttR97F1 iONDY2xibf7hbfjHjTofra9xW6rx+oxp5SIxdXQw= Received: by mail-wm1-f43.google.com with SMTP id n133so541075wmd.4 for ; Wed, 28 Nov 2018 17:41:06 -0800 (PST) X-Gm-Message-State: AA+aEWYhxoBJeFJTKACfeQMqysNeA2G17Dsp2bNPco/fuXxil4avwy4k 5SK3Cu5a4LZ2Ce8ArSlDnhHaPnaCv3KYF7T7ZapLtg== X-Google-Smtp-Source: AFSGD/WfoTkNsD/SpIzGyHzxniNM/V3LNo5UXO6L2pLTY97A3RtZ4/fbzhf69z5mARk/D5a9sQm6+eazl13xJb2C6bQ= X-Received: by 2002:a1c:aacf:: with SMTP id t198-v6mr4621742wme.108.1543455665079; Wed, 28 Nov 2018 17:41:05 -0800 (PST) MIME-Version: 1.0 References: <20181128000754.18056-1-rick.p.edgecombe@intel.com> <20181128000754.18056-3-rick.p.edgecombe@intel.com> In-Reply-To: <20181128000754.18056-3-rick.p.edgecombe@intel.com> From: Andy Lutomirski Date: Wed, 28 Nov 2018 17:40:53 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 2/2] x86/modules: Make x86 allocs to flush when free To: Rick Edgecombe Cc: Andrew Morton , Andrew Lutomirski , Will Deacon , Linux-MM , LKML , Kernel Hardening , "Naveen N . Rao" , Anil S Keshavamurthy , "David S. Miller" , Masami Hiramatsu , Steven Rostedt , Ingo Molnar , Alexei Starovoitov , Daniel Borkmann , jeyu@kernel.org, Network Development , Ard Biesheuvel , Jann Horn , Kristen Carlson Accardi , Dave Hansen , "Dock, Deneen T" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Nov 27, 2018, at 4:07 PM, Rick Edgecombe = wrote: > > Change the module allocations to flush before freeing the pages. > > Signed-off-by: Rick Edgecombe > --- > arch/x86/kernel/module.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c > index b052e883dd8c..1694daf256b3 100644 > --- a/arch/x86/kernel/module.c > +++ b/arch/x86/kernel/module.c > @@ -87,8 +87,8 @@ void *module_alloc(unsigned long size) > p =3D __vmalloc_node_range(size, MODULE_ALIGN, > MODULES_VADDR + get_module_load_offset(), > MODULES_END, GFP_KERNEL, > - PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, > - __builtin_return_address(0)); > + PAGE_KERNEL_EXEC, VM_IMMEDIATE_UNMAP, > + NUMA_NO_NODE, __builtin_return_address(0)); Hmm. How awful is the resulting performance for heavy eBPF users? I=E2=80= =99m wondering if the JIT will need some kind of cache to reuse allocations. > if (p && (kasan_module_alloc(p, size) < 0)) { > vfree(p); > return NULL; > -- > 2.17.1 >