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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE69AC6379F for ; Tue, 21 Feb 2023 08:31:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2F6FF6B0073; Tue, 21 Feb 2023 03:31:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2803D6B0074; Tue, 21 Feb 2023 03:31:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0D5226B0075; Tue, 21 Feb 2023 03:31:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id EC0A86B0073 for ; Tue, 21 Feb 2023 03:31:18 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id C5EA51C6992 for ; Tue, 21 Feb 2023 08:31:18 +0000 (UTC) X-FDA: 80490629436.10.E81B594 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf18.hostedemail.com (Postfix) with ESMTP id 343D81C000F for ; Tue, 21 Feb 2023 08:31:16 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="YJzcZx/B"; spf=pass (imf18.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1676968276; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=kCboO0D4l0fCcmSpxKOmwRfVm5IgZzSNbPLhAcKwBhQ=; b=dEfmHc5tTmGdUI8sX0DZh1VRvmpwrDYwSSyHmd9YqZjMXcuqLQZwl5AJZNApJ1NgjQyINE OR6+eAjY6Fve0GsZcpFepzQP4GCHoPuF0/7vPHircIcqdWexdz/Pn4p15IfttrlUkTFu2x V+L/kIpnDBGkF4oiwFErKyRsdVGNCEs= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="YJzcZx/B"; spf=pass (imf18.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1676968276; a=rsa-sha256; cv=none; b=u8mXfAsvti1MouGvc/RBCJCOL1WJ0PvBSdJchY9nU8iSCuxQWRUUUD4cuVHKcklXTsWFzI at3G1z3A5SSvs5NJ94uyYTL2rH0eb1JdfmaelQyTibCn03htnRKlp/zwlWC40akkbZ8gUo q2iUQZnM9rodlcjIBUB3YlGR5anlZww= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1676968275; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kCboO0D4l0fCcmSpxKOmwRfVm5IgZzSNbPLhAcKwBhQ=; b=YJzcZx/BYTWMyJ7vp9Ob1cUCbqQiZE6gYxhE8I/ebO0OZxILgEy3wLFuxb3CFf9+RMsdc+ kCDMPaSpl6zGwnwJvqJ/2u4qpf5tRlS/eBcm7qQ8JTMr38Z9T6BFfaRXGREcAGQaPejLGv IyI+SLgOfWZryCjkHePs085IgCdSGUE= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-584-LBomPhRCM9ysEp0k55IyTw-1; Tue, 21 Feb 2023 03:31:14 -0500 X-MC-Unique: LBomPhRCM9ysEp0k55IyTw-1 Received: by mail-wm1-f69.google.com with SMTP id x18-20020a1c7c12000000b003e1e7d3cf9fso1787070wmc.3 for ; Tue, 21 Feb 2023 00:31:14 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:organization:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=kCboO0D4l0fCcmSpxKOmwRfVm5IgZzSNbPLhAcKwBhQ=; b=pl/7VMDix6BMGYSKmBo5/oMJGIF2kV0SsXKz45DvR1GWwq/9j4f6SvkVg6NYPiqQUW zAO/kA0bVLgWPOZKDOxhWxe357Ny3iwTsksvyjO/mFLQQHjQCBuFOmqOnsUKCnqV9Jei sTbWNJmxrOW+uDszQABfN78ICEBWgyT1OqIn/DLbgxR50wltdF2lJTYSd7/6U05nEhbx 7Vlzs+zm/naa7LpZlHrQmh6vw9xFB+ZwG0qCg1GXpXexBxolaBXnxnBfZYcCpAFEi1Tj jIR1dSX5wNbp+QJQAXBospaaaEmsG8Vu3tFkzbIQikIuOXZ0G/0mCwiOWHV6hsUuqBgf KHaA== X-Gm-Message-State: AO0yUKWNHNuKXn4kBlEag93koGBzjeVZWEHeudgh7TKwYaEJwuYnE3+S 83m1jzhq50g9CfmbPAR0dSq2ZcczDlfEl9h4wvpMuUlig3QavrzMDLx5FgQtEGs/yhuR8eWPi/S mASgjoBd5sFk= X-Received: by 2002:a05:600c:1f06:b0:3dc:3b29:7a4 with SMTP id bd6-20020a05600c1f0600b003dc3b2907a4mr3260181wmb.0.1676968273153; Tue, 21 Feb 2023 00:31:13 -0800 (PST) X-Google-Smtp-Source: AK7set+0r8eJK1vTBbYZl8FFEvRCCuV3a2A3iN25xytv7tuI4shMZpsPvaSTp+HX4M0GCokqILTrPQ== X-Received: by 2002:a05:600c:1f06:b0:3dc:3b29:7a4 with SMTP id bd6-20020a05600c1f0600b003dc3b2907a4mr3260139wmb.0.1676968272718; Tue, 21 Feb 2023 00:31:12 -0800 (PST) Received: from ?IPV6:2003:cb:c707:4800:aecc:dadb:40a8:ce81? (p200300cbc7074800aeccdadb40a8ce81.dip0.t-ipconnect.de. [2003:cb:c707:4800:aecc:dadb:40a8:ce81]) by smtp.gmail.com with ESMTPSA id 26-20020a05600c229a00b003dc49e0132asm3583198wmf.1.2023.02.21.00.31.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Feb 2023 00:31:12 -0800 (PST) Message-ID: Date: Tue, 21 Feb 2023 09:31:10 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.2 Subject: Re: [PATCH v6 22/41] mm/mmap: Add shadow stack pages to memory accounting To: "Edgecombe, Rick P" , "bsingharora@gmail.com" , "hpa@zytor.com" , "Syromiatnikov, Eugene" , "peterz@infradead.org" , "rdunlap@infradead.org" , "keescook@chromium.org" , "dave.hansen@linux.intel.com" , "kirill.shutemov@linux.intel.com" , "Eranian, Stephane" , "linux-mm@kvack.org" , "fweimer@redhat.com" , "nadav.amit@gmail.com" , "jannh@google.com" , "dethoma@microsoft.com" , "linux-arch@vger.kernel.org" , "kcc@google.com" , "pavel@ucw.cz" , "oleg@redhat.com" , "hjl.tools@gmail.com" , "bp@alien8.de" , "Lutomirski, Andy" , "linux-doc@vger.kernel.org" , "arnd@arndb.de" , "tglx@linutronix.de" , "Schimpe, Christina" , "x86@kernel.org" , "mike.kravetz@oracle.com" , "Yang, Weijiang" , "debug@rivosinc.com" , "jamorris@linux.microsoft.com" , "john.allen@amd.com" , "rppt@kernel.org" , "andrew.cooper3@citrix.com" , "mingo@redhat.com" , "corbet@lwn.net" , "linux-kernel@vger.kernel.org" , "linux-api@vger.kernel.org" , "gorcunov@gmail.com" , "akpm@linux-foundation.org" Cc: "Yu, Yu-cheng" References: <20230218211433.26859-1-rick.p.edgecombe@intel.com> <20230218211433.26859-23-rick.p.edgecombe@intel.com> <6ccc8d30-336a-12af-1179-5dc4eca3048d@redhat.com> <8bd58778e062bb9526c905c5573a2ee20cb41eef.camel@intel.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: <8bd58778e062bb9526c905c5573a2ee20cb41eef.camel@intel.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 343D81C000F X-Stat-Signature: 1srrctqpe5dt4nwnk94nfifwfnmrbhky X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1676968276-138658 X-HE-Meta: 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 XgUATROX 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 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 20.02.23 23:44, Edgecombe, Rick P wrote: > On Mon, 2023-02-20 at 13:58 +0100, David Hildenbrand wrote: >> On 18.02.23 22:14, Rick Edgecombe wrote: >>> From: Yu-cheng Yu >>> >>> The x86 Control-flow Enforcement Technology (CET) feature includes >>> a new >>> type of memory called shadow stack. This shadow stack memory has >>> some >>> unusual properties, which requires some core mm changes to function >>> properly. >>> >>> Account shadow stack pages to stack memory. >>> >>> Reviewed-by: Kees Cook >>> Tested-by: Pengfei Xu >>> Tested-by: John Allen >>> Signed-off-by: Yu-cheng Yu >>> Co-developed-by: Rick Edgecombe >>> Signed-off-by: Rick Edgecombe >>> Cc: Kees Cook >>> >>> --- >>> v3: >>> - Remove unneeded VM_SHADOW_STACK check in accountable_mapping() >>> (Kirill) >>> >>> v2: >>> - Remove is_shadow_stack_mapping() and just change it to >>> directly bitwise >>> and VM_SHADOW_STACK. >>> >>> Yu-cheng v26: >>> - Remove redundant #ifdef CONFIG_MMU. >>> >>> Yu-cheng v25: >>> - Remove #ifdef CONFIG_ARCH_HAS_SHADOW_STACK for >>> is_shadow_stack_mapping(). >>> --- >>> mm/mmap.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/mm/mmap.c b/mm/mmap.c >>> index 425a9349e610..9f85596cce31 100644 >>> --- a/mm/mmap.c >>> +++ b/mm/mmap.c >>> @@ -3290,6 +3290,8 @@ void vm_stat_account(struct mm_struct *mm, >>> vm_flags_t flags, long npages) >>> mm->exec_vm += npages; >>> else if (is_stack_mapping(flags)) >>> mm->stack_vm += npages; >>> + else if (flags & VM_SHADOW_STACK) >>> + mm->stack_vm += npages; >> >> Why not modify is_stack_mapping() ? > > It kind of sticks out a little in this conditional, but > is_stack_mapping() has this comment: > /* > * Stack area - automatically grows in one direction > * > * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous: > * do_mmap() forbids all other combinations. > */ > > Shadow stack don't grow, so it doesn't quite fit. There used to be an > is_shadow_stack_mapping(), but it was removed because all that was > needed (for the time being) was the simple bitwise AND: > > https://lore.kernel.org/lkml/804adbac-61e6-0fd2-f726-5735fb290199@intel.com/ As there is only a single user of is_stack_mapping(), I'd simply have adjusted the doc of is_stack_mapping() to include shadow stacks. -- Thanks, David / dhildenb