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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 D8BD3C4707E for ; Sat, 22 May 2021 01:58:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 650F2613DB for ; Sat, 22 May 2021 01:58:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 650F2613DB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7E6CA8E007C; Fri, 21 May 2021 21:58:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 796858E0079; Fri, 21 May 2021 21:58:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5E9588E007C; Fri, 21 May 2021 21:58:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0168.hostedemail.com [216.40.44.168]) by kanga.kvack.org (Postfix) with ESMTP id 2C0B78E0079 for ; Fri, 21 May 2021 21:58:21 -0400 (EDT) Received: from smtpin38.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id A8DF86132 for ; Sat, 22 May 2021 01:58:20 +0000 (UTC) X-FDA: 78167207160.38.89D1A34 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by imf15.hostedemail.com (Postfix) with ESMTP id 93AADA0001C0 for ; Sat, 22 May 2021 01:58:16 +0000 (UTC) IronPort-SDR: tSDTdCjD1A5JGvvX5GYRAKtCcQEJqvG2KrP0RQEojVXVveU/7avD3bIikVfs7zHfb0sKrqHu65 ++b9ngFTHfjw== X-IronPort-AV: E=McAfee;i="6200,9189,9991"; a="181219164" X-IronPort-AV: E=Sophos;i="5.82,319,1613462400"; d="scan'208";a="181219164" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 May 2021 18:58:16 -0700 IronPort-SDR: IS1a1WjJpDP/oMTDY7yRQl6/vLIwFp04ZRQAZ3ziPozZVC+dJYHKaJK5SF3eo2OzyVejVGMg9A Ua3eWG277zeg== X-IronPort-AV: E=Sophos;i="5.82,319,1613462400"; d="scan'208";a="395558527" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.254.177.76]) ([10.254.177.76]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 May 2021 18:58:14 -0700 Subject: Re: [PATCH v27 13/31] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 To: Axel Rasmussen Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , LKML , linux-doc@vger.kernel.org, Linux MM , 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 , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang , Peter Xu References: <20210521221211.29077-1-yu-cheng.yu@intel.com> <20210521221211.29077-14-yu-cheng.yu@intel.com> From: "Yu, Yu-cheng" Message-ID: <74057265-c148-98bf-9ada-21328b160227@intel.com> Date: Fri, 21 May 2021 18:58:14 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 93AADA0001C0 Authentication-Results: imf15.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf15.hostedemail.com: domain of yu-cheng.yu@intel.com has no SPF policy when checking 192.55.52.136) smtp.mailfrom=yu-cheng.yu@intel.com X-Rspamd-Server: rspam04 X-Stat-Signature: 7p3zffyiuf7y418u8jtcb4x19oojohxs X-HE-Tag: 1621648696-518672 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 5/21/2021 3:25 PM, Axel Rasmussen wrote: > This seems reasonable to me. The particular bit used isn't so > important from my perspective. I can't think of a way this would break > backward compatibility or such. So: > > Reviewed-by: Axel Rasmussen Thanks! Yu-cheng > > On Fri, May 21, 2021 at 3:13 PM Yu-cheng Yu wrote: >> >> To introduce VM_SHADOW_STACK as VM_HIGH_ARCH_BIT (37), and make all >> VM_HIGH_ARCH_BITs stay together, move VM_UFFD_MINOR_BIT from 37 to 38. >> >> Signed-off-by: Yu-cheng Yu >> Cc: Axel Rasmussen >> 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 c274f75efcf9..923f89b9f1b5 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -373,7 +373,7 @@ 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 >> -- >> 2.21.0 >>