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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 429B5C74A5B for ; Sun, 19 Mar 2023 00:19:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229926AbjCSATK (ORCPT ); Sat, 18 Mar 2023 20:19:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230156AbjCSASV (ORCPT ); Sat, 18 Mar 2023 20:18:21 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DD832A6EE; Sat, 18 Mar 2023 17:17:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1679185036; x=1710721036; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=Za8k1YHP/NKzL9PLFScEe9Ide1J8X/tcTz7SUA3IT3Y=; b=CuNWZCLKvehmV2IW7nIXkP8BFvTWA4GN1+YLjm3EbCE0S3JUTwrs4rx0 5BUEG64yj+3ltWxBJ/wN/D7gSE1mMyX9k6N3KoPACkWd+ZBPAN0DLTHK5 80+sATCYt5fqo/z8t3NNysRUpI3YbVzRyzvEa06nOMX4DOcwaP4Nj28on I5ZLaz9RM93Vy5bDiYRWXwwtoPjrBePAn7hJh9jKUSjJyXivGZ9C3n/H2 Oo6ZbFTLI8foIJMdxP1QC6Ff7+f2dgGcxz0PrE9a7FALW1Kf+NUypmcaI mQ9Ez/on+wI8eD8uyr9IVjYQNm9HlJWuDhKnQMh9ffpVO//NW2GbGQoaV g==; X-IronPort-AV: E=McAfee;i="6600,9927,10653"; a="338491095" X-IronPort-AV: E=Sophos;i="5.98,272,1673942400"; d="scan'208";a="338491095" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2023 17:16:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10653"; a="749672849" X-IronPort-AV: E=Sophos;i="5.98,272,1673942400"; d="scan'208";a="749672849" Received: from bmahatwo-mobl1.gar.corp.intel.com (HELO rpedgeco-desk.amr.corp.intel.com) ([10.135.34.5]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2023 17:16:21 -0700 From: Rick Edgecombe To: x86@kernel.org, "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , Weijiang Yang , "Kirill A . Shutemov" , John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com, akpm@linux-foundation.org, Andrew.Cooper3@citrix.com, christina.schimpe@intel.com, david@redhat.com, debug@rivosinc.com, szabolcs.nagy@arm.com Cc: rick.p.edgecombe@intel.com, Yu-cheng Yu Subject: [PATCH v8 17/40] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 Date: Sat, 18 Mar 2023 17:15:12 -0700 Message-Id: <20230319001535.23210-18-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230319001535.23210-1-rick.p.edgecombe@intel.com> References: <20230319001535.23210-1-rick.p.edgecombe@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org 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. Future patches will introduce a new VM flag VM_SHADOW_STACK that will be VM_HIGH_ARCH_BIT_5. VM_HIGH_ARCH_BIT_1 through VM_HIGH_ARCH_BIT_4 are bits 32-36, and bit 37 is the unrelated VM_UFFD_MINOR_BIT. For the sake of order, make all VM_HIGH_ARCH_BITs stay together by moving VM_UFFD_MINOR_BIT from 37 to 38. This will allow VM_SHADOW_STACK to be introduced as 37. Co-developed-by: Rick Edgecombe Signed-off-by: Yu-cheng Yu Signed-off-by: Rick Edgecombe Reviewed-by: Kees Cook Reviewed-by: Axel Rasmussen Acked-by: Mike Rapoport (IBM) Acked-by: Peter Xu Tested-by: Pengfei Xu Tested-by: John Allen Tested-by: Kees Cook --- include/linux/mm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index af652444fbba..a1b31caae013 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -377,7 +377,7 @@ extern unsigned int kobjsize(const void *objp); #endif #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR -# define VM_UFFD_MINOR_BIT 37 +# define VM_UFFD_MINOR_BIT 38 # define VM_UFFD_MINOR BIT(VM_UFFD_MINOR_BIT) /* UFFD minor faults */ #else /* !CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */ # define VM_UFFD_MINOR VM_NONE -- 2.17.1