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 A2EF2C61DA4 for ; Sat, 18 Feb 2023 21:20:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229898AbjBRVUC (ORCPT ); Sat, 18 Feb 2023 16:20:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230128AbjBRVTH (ORCPT ); Sat, 18 Feb 2023 16:19:07 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1A151A67D; Sat, 18 Feb 2023 13:17:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1676755035; x=1708291035; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=o/D1WjgTvHa+RZFY0t2cOsdLZJ4ujw/CAZDldCJEJW8=; b=CYQNe2Kj07Y4Vr6hAyjLj7UWnek7drWp/dDDSJlnMX+TDukBjZGm1b+U x/emMHTx7FYm0OQ/XprERdHEuZyjZAl3AqzqgNU9+bEPGD2L4VfGf41Lu /yltU/3e/u8S2xpv/+2Ab3Xzs5bsO8+YCzXKYxxsUovHlyKtVsDuD6E+4 mutJAnKeZlPhEPOGVkLuSJY18Dl/U1fsrNHK+LvxCqpbpg5PGNm3LK131 qEGRb1wGdPml70kb2dYejdLaQMpbRLyIAj1zG65GiuDXLRyAs89e6UOTW L0qmFRH67wOF1CIBi1y+1vdfariOehhoeExqC4czWaCp/d1z0Tj2AeC6P Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10625"; a="418427458" X-IronPort-AV: E=Sophos;i="5.97,309,1669104000"; d="scan'208";a="418427458" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2023 13:16:11 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10625"; a="664241653" X-IronPort-AV: E=Sophos;i="5.97,309,1669104000"; d="scan'208";a="664241653" Received: from adityava-mobl1.amr.corp.intel.com (HELO rpedgeco-desk.amr.corp.intel.com) ([10.209.80.223]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2023 13:16:10 -0800 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 Cc: rick.p.edgecombe@intel.com, Yu-cheng Yu , Peter Xu Subject: [PATCH v6 17/41] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 Date: Sat, 18 Feb 2023 13:14:09 -0800 Message-Id: <20230218211433.26859-18-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230218211433.26859-1-rick.p.edgecombe@intel.com> References: <20230218211433.26859-1-rick.p.edgecombe@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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. Tested-by: Pengfei Xu Tested-by: John Allen Reviewed-by: Kees Cook Acked-by: Peter Xu Signed-off-by: Yu-cheng Yu Reviewed-by: Axel Rasmussen Signed-off-by: Rick Edgecombe Cc: Peter Xu Cc: Mike Kravetz --- 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 4650e2580d60..e6f1789c8e69 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -366,7 +366,7 @@ 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