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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 9AD48C433E0 for ; Thu, 18 Jun 2020 13:50:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8010D207E8 for ; Thu, 18 Jun 2020 13:50:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730545AbgFRNuc (ORCPT ); Thu, 18 Jun 2020 09:50:32 -0400 Received: from verein.lst.de ([213.95.11.211]:49162 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730269AbgFRNub (ORCPT ); Thu, 18 Jun 2020 09:50:31 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 0D7846736F; Thu, 18 Jun 2020 15:50:28 +0200 (CEST) Date: Thu, 18 Jun 2020 15:50:27 +0200 From: Christoph Hellwig To: Peter Zijlstra Cc: David Hildenbrand , Christoph Hellwig , Andrew Morton , Dexuan Cui , Vitaly Kuznetsov , 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: <20200618135027.GA23534@lst.de> References: <20200618064307.32739-1-hch@lst.de> <20200618064307.32739-3-hch@lst.de> <90234f58-e83a-7f20-62a7-80a4e81cde95@redhat.com> <20200618103506.GH576905@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200618103506.GH576905@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 18, 2020 at 12:35:06PM +0200, Peter Zijlstra wrote: > On Thu, Jun 18, 2020 at 10:55:58AM +0200, David Hildenbrand wrote: > > On 18.06.20 08:43, Christoph Hellwig wrote: > > > Use PAGE_KERNEL_ROX directly instead of allocating RWX and setting the > > > page read-only just after the allocation. > > > > > > Signed-off-by: Christoph Hellwig > > > --- > > > arch/arm64/kernel/probes/kprobes.c | 12 +++--------- > > > 1 file changed, 3 insertions(+), 9 deletions(-) > > > > > > diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c > > > index d1c95dcf1d7833..cbe49cd117cfec 100644 > > > --- 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__); > > > > I do wonder if something like vmalloc_prot(size, prot) would make this > > (and the other two users) easier to read. > > > > So instead of ripping out vmalloc_exec(), converting it into > > vmalloc_prot() instead. > > > > Did you consider that? > > For x86 Christoph did module_alloc_prot(), which is in his more > extensive set of patches addressing this. I suspect that would be the > right thing for ARM64 as well. Yes. The somewhat hacky way I added it cause problems for UML, so I instead plan to do a series converting all architectures over to module_alloc_prot, plus lots of other cleanups in the area that I noticed. I don't think vmalloc_prot is a good idea per se, as there only few potential users, and I don't want too many vmalloc APIs. 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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 E4E1DC433DF for ; Thu, 18 Jun 2020 13:50:47 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A905920656 for ; Thu, 18 Jun 2020 13:50:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="eB3DGAQg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A905920656 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ZkW6BNFiZmVch13uoeYrJJiLjr7Rywf7i75RsF7wgSg=; b=eB3DGAQgEF9Wo5 SZSC/cbFcRQGxtkemh5nd9oLDaQdsINoJpyIRecZM4Gf8GtKvVzt1EtNbAXbncGR5FpCzTX0BrtV8 jBbUc1aBEYwwZDyibq+Xf/qLeC0+J0i6m1tAsdmttSeof8wmn7WjPdFAjEJC42KcsHzYGkSMaecFN mFI8x1PiBdcBRN5dQMzGCLSqBP+aMEjJdj6krg064gVnX214Eh/wvf+2YNY1op2CFUeFaYr9Qib6a KakZFrQE3JDTTdkdxJuVMwQzRv2IMKSW4e1Ryrx/PYQk7w1etmy+2e9CRhS//yliiROJ91cDfq3jE bLhHp4sIXZqSHi/TNxyA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jluwA-00016T-Gl; Thu, 18 Jun 2020 13:50:38 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jluw6-00015P-Mx for linux-arm-kernel@lists.infradead.org; Thu, 18 Jun 2020 13:50:36 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 0D7846736F; Thu, 18 Jun 2020 15:50:28 +0200 (CEST) Date: Thu, 18 Jun 2020 15:50:27 +0200 From: Christoph Hellwig To: Peter Zijlstra Subject: Re: [PATCH 2/3] arm64: use PAGE_KERNEL_ROX directly in alloc_insn_page Message-ID: <20200618135027.GA23534@lst.de> References: <20200618064307.32739-1-hch@lst.de> <20200618064307.32739-3-hch@lst.de> <90234f58-e83a-7f20-62a7-80a4e81cde95@redhat.com> <20200618103506.GH576905@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200618103506.GH576905@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200618_065034_898262_0690E263 X-CRM114-Status: GOOD ( 20.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-hyperv@vger.kernel.org, David Hildenbrand , Catalin Marinas , x86@kernel.org, Dexuan Cui , linux-kernel@vger.kernel.org, Christoph Hellwig , linux-mm@kvack.org, Jessica Yu , Vitaly Kuznetsov , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jun 18, 2020 at 12:35:06PM +0200, Peter Zijlstra wrote: > On Thu, Jun 18, 2020 at 10:55:58AM +0200, David Hildenbrand wrote: > > On 18.06.20 08:43, Christoph Hellwig wrote: > > > Use PAGE_KERNEL_ROX directly instead of allocating RWX and setting the > > > page read-only just after the allocation. > > > > > > Signed-off-by: Christoph Hellwig > > > --- > > > arch/arm64/kernel/probes/kprobes.c | 12 +++--------- > > > 1 file changed, 3 insertions(+), 9 deletions(-) > > > > > > diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c > > > index d1c95dcf1d7833..cbe49cd117cfec 100644 > > > --- 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__); > > > > I do wonder if something like vmalloc_prot(size, prot) would make this > > (and the other two users) easier to read. > > > > So instead of ripping out vmalloc_exec(), converting it into > > vmalloc_prot() instead. > > > > Did you consider that? > > For x86 Christoph did module_alloc_prot(), which is in his more > extensive set of patches addressing this. I suspect that would be the > right thing for ARM64 as well. Yes. The somewhat hacky way I added it cause problems for UML, so I instead plan to do a series converting all architectures over to module_alloc_prot, plus lots of other cleanups in the area that I noticed. I don't think vmalloc_prot is a good idea per se, as there only few potential users, and I don't want too many vmalloc APIs. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel