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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 88E23C433DF for ; Sun, 21 Jun 2020 02:16:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53FC92310A for ; Sun, 21 Jun 2020 02:16:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592705781; bh=AmHDVslR6mKNgf2o33y0VkLCChUaTWfNm0pSDs+MYak=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=KDWM0OBLJCsoVGIYqFJin7DvQ1b4YWJhr+Zp0MjE55z9VH6DVgW8w2RHQuIoXrjxo aY586uDFSvn5gtp60lGLd2nrJ7khQQ0fgABiMf0JBYYOUTxBsPpf5PARGjRmFMRBWE MVEpv0OVKraF1P3+Ve97bcTVgW2IZmNEEK/n4t1c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729085AbgFUCQV (ORCPT ); Sat, 20 Jun 2020 22:16:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:39714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729080AbgFUCQU (ORCPT ); Sat, 20 Jun 2020 22:16:20 -0400 Received: from X1 (nat-ab2241.sltdut.senawave.net [162.218.216.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E65E32186A; Sun, 21 Jun 2020 02:16:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592705779; bh=AmHDVslR6mKNgf2o33y0VkLCChUaTWfNm0pSDs+MYak=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ocFQKCnNtHEou6r7kB9zbA1+GZl5pJ4akGjW/+mAhePiZUT4eat4WTQgjo6xEFQw8 oW4eF04QeOHGI/AAxBdrzYJaqC1voLTCWjnrlSBHiE5f51Opg1XYlOn4CFPWKADuka s/ZJhpHXuIStXjWYhDQasn2LaNblO273QcPnHiAs= Date: Sat, 20 Jun 2020 19:16:16 -0700 From: Andrew Morton To: Christoph Hellwig Cc: Dexuan Cui , Vitaly Kuznetsov , Peter Zijlstra , Catalin Marinas , Will Deacon , Jessica Yu , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 2/3] arm64: use PAGE_KERNEL_ROX directly in alloc_insn_page Message-Id: <20200620191616.bae356186ba3329ade67bbf7@linux-foundation.org> In-Reply-To: <20200618064307.32739-3-hch@lst.de> References: <20200618064307.32739-1-hch@lst.de> <20200618064307.32739-3-hch@lst.de> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-hyperv-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Thu, 18 Jun 2020 08:43:06 +0200 Christoph Hellwig wrote: > Use PAGE_KERNEL_ROX directly instead of allocating RWX and setting the > page read-only just after the allocation. > > --- a/arch/arm64/kernel/probes/kprobes.c > +++ b/arch/arm64/kernel/probes/kprobes.c > @@ -120,15 +120,9 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) > > void *alloc_insn_page(void) > { > - void *page; > - > - page = vmalloc_exec(PAGE_SIZE); > - if (page) { > - set_memory_ro((unsigned long)page, 1); > - set_vm_flush_reset_perms(page); > - } > - > - return page; > + return __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END, > + GFP_KERNEL, PAGE_KERNEL_ROX, VM_FLUSH_RESET_PERMS, > + NUMA_NO_NODE, __func__); > } > > /* arm kprobe: install breakpoint in text */ But why. I think this is just a cleanup, doesn't address any runtime issue?