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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 C1283C2D0E4 for ; Sun, 15 Nov 2020 08:51:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A5742242E for ; Sun, 15 Nov 2020 08:51:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mvUrkC8D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726710AbgKOIp7 (ORCPT ); Sun, 15 Nov 2020 03:45:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:59768 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726600AbgKOIpz (ORCPT ); Sun, 15 Nov 2020 03:45:55 -0500 Received: from kernel.org (unknown [77.125.7.142]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AC352223FB; Sun, 15 Nov 2020 08:45:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605429954; bh=I2e6oiG56Ipc+LYVEf48Tzpdu9e5X2SPeAjMkXGJ+FY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mvUrkC8DbWSBeGtX5LmBQbQw3erYKhs5cOaKJid6GDJMPM7nXXubIxoNcBB3oGNe7 rCwIs49LamtntTc1amgIjfXRya2sb8UfoqlV6jooN7E3J+NN/S80wRZL4M8ZXWanKD tXrCqT3L+M5TGE/FDZPfoLrZTF0AQQmH6gi3Hxpk= Date: Sun, 15 Nov 2020 10:45:39 +0200 From: Mike Rapoport To: Matthew Wilcox Cc: Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , David Hildenbrand , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org, Hagen Paul Pfeifer Subject: Re: [PATCH v8 4/9] mm: introduce memfd_secret system call to create "secret" memory areas Message-ID: <20201115084539.GU4758@kernel.org> References: <20201110151444.20662-1-rppt@kernel.org> <20201110151444.20662-5-rppt@kernel.org> <20201113140656.GG17076@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201113140656.GG17076@casper.infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Fri, Nov 13, 2020 at 02:06:56PM +0000, Matthew Wilcox wrote: > On Tue, Nov 10, 2020 at 05:14:39PM +0200, Mike Rapoport wrote: > > diff --git a/mm/Kconfig b/mm/Kconfig > > index c89c5444924b..d8d170fa5210 100644 > > --- a/mm/Kconfig > > +++ b/mm/Kconfig > > @@ -884,4 +884,7 @@ config ARCH_HAS_HUGEPD > > config MAPPING_DIRTY_HELPERS > > bool > > > > +config SECRETMEM > > + def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED > > So I now have to build this in, whether I want it or not? Why wouldn't anybody want this nice feature? ;-) Now, seriously, I hesitated a lot about having a prompt here, but in the end I've decided to go without it. The added footprint is not so big, with x86 defconfig it's less than 8K and with distro (I've checked with Fedora) config the difference is less than 1k because they anyway have CMA=y. As this is "security" feature, disros most probably would have this enabled anyway, and I believe users that will see something like "Allow hiding memory from the kernel" will hit Y there. -- Sincerely yours, Mike. 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=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 77F79C2D0E4 for ; Sun, 15 Nov 2020 08:45:58 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (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 112502242E for ; Sun, 15 Nov 2020 08:45:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mvUrkC8D" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 112502242E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id C77C2100EF270; Sun, 15 Nov 2020 00:45:57 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=rppt@kernel.org; receiver= Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 64ED1100EF26E for ; Sun, 15 Nov 2020 00:45:55 -0800 (PST) Received: from kernel.org (unknown [77.125.7.142]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AC352223FB; Sun, 15 Nov 2020 08:45:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605429954; bh=I2e6oiG56Ipc+LYVEf48Tzpdu9e5X2SPeAjMkXGJ+FY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mvUrkC8DbWSBeGtX5LmBQbQw3erYKhs5cOaKJid6GDJMPM7nXXubIxoNcBB3oGNe7 rCwIs49LamtntTc1amgIjfXRya2sb8UfoqlV6jooN7E3J+NN/S80wRZL4M8ZXWanKD tXrCqT3L+M5TGE/FDZPfoLrZTF0AQQmH6gi3Hxpk= Date: Sun, 15 Nov 2020 10:45:39 +0200 From: Mike Rapoport To: Matthew Wilcox Subject: Re: [PATCH v8 4/9] mm: introduce memfd_secret system call to create "secret" memory areas Message-ID: <20201115084539.GU4758@kernel.org> References: <20201110151444.20662-1-rppt@kernel.org> <20201110151444.20662-5-rppt@kernel.org> <20201113140656.GG17076@casper.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201113140656.GG17076@casper.infradead.org> Message-ID-Hash: IBHF3DZGQU6JJQH5PGD63AUVKC5N2774 X-Message-ID-Hash: IBHF3DZGQU6JJQH5PGD63AUVKC5N2774 X-MailFrom: rppt@kernel.org X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dave Hansen , David Hildenbrand , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.ker nel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org, Hagen Paul Pfeifer X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Fri, Nov 13, 2020 at 02:06:56PM +0000, Matthew Wilcox wrote: > On Tue, Nov 10, 2020 at 05:14:39PM +0200, Mike Rapoport wrote: > > diff --git a/mm/Kconfig b/mm/Kconfig > > index c89c5444924b..d8d170fa5210 100644 > > --- a/mm/Kconfig > > +++ b/mm/Kconfig > > @@ -884,4 +884,7 @@ config ARCH_HAS_HUGEPD > > config MAPPING_DIRTY_HELPERS > > bool > > > > +config SECRETMEM > > + def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED > > So I now have to build this in, whether I want it or not? Why wouldn't anybody want this nice feature? ;-) Now, seriously, I hesitated a lot about having a prompt here, but in the end I've decided to go without it. The added footprint is not so big, with x86 defconfig it's less than 8K and with distro (I've checked with Fedora) config the difference is less than 1k because they anyway have CMA=y. As this is "security" feature, disros most probably would have this enabled anyway, and I believe users that will see something like "Allow hiding memory from the kernel" will hit Y there. -- Sincerely yours, Mike. _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org 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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 1F592C2D0E4 for ; Sun, 15 Nov 2020 08:46:16 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 BF26C2242E for ; Sun, 15 Nov 2020 08:46:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="08S9wY0j"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mvUrkC8D" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF26C2242E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.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=fskdr2pGhBO4YndhV64Bl+bjohnqEeQbg82Meld+XKI=; b=08S9wY0jqJxwO2D2+HRrv5I6f F4H9GKth2IPGmhlrQmwMu6PxKexvwcaFibs5eRiNOF8pkLjcOhuRSMWCy04Oo+seJ+meIsCqQrROH dpXn7wbb6CUdPxKHdwRKvfPnbGUdpjs3Rw4Ty6WtlVfKdSWnryI1P2U+exOCVaQ6blC93DkQpEWpg ljPU2FH3+ciwbGntpgklQNWig435qfvQvzJ3YijySP5GpqdZ0Suv8pC6fj53bA8Rwj5sO3OgVvPwQ 4XW5AbukQJDaYcybbo4MWGjQBeqjFjn4tL+uvdFLe5AoMGHojnBNdCxlMVdISEjuUroXw/vmq1ZI6 D1JgCppqg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1keDfe-00019Y-EY; Sun, 15 Nov 2020 08:46:02 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1keDfY-00017v-1Y; Sun, 15 Nov 2020 08:45:57 +0000 Received: from kernel.org (unknown [77.125.7.142]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AC352223FB; Sun, 15 Nov 2020 08:45:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605429954; bh=I2e6oiG56Ipc+LYVEf48Tzpdu9e5X2SPeAjMkXGJ+FY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mvUrkC8DbWSBeGtX5LmBQbQw3erYKhs5cOaKJid6GDJMPM7nXXubIxoNcBB3oGNe7 rCwIs49LamtntTc1amgIjfXRya2sb8UfoqlV6jooN7E3J+NN/S80wRZL4M8ZXWanKD tXrCqT3L+M5TGE/FDZPfoLrZTF0AQQmH6gi3Hxpk= Date: Sun, 15 Nov 2020 10:45:39 +0200 From: Mike Rapoport To: Matthew Wilcox Subject: Re: [PATCH v8 4/9] mm: introduce memfd_secret system call to create "secret" memory areas Message-ID: <20201115084539.GU4758@kernel.org> References: <20201110151444.20662-1-rppt@kernel.org> <20201110151444.20662-5-rppt@kernel.org> <20201113140656.GG17076@casper.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201113140656.GG17076@casper.infradead.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201115_034556_224767_7D615350 X-CRM114-Status: GOOD ( 17.75 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , David Hildenbrand , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, "H. Peter Anvin" , Christopher Lameter , Shuah Khan , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Will Deacon , x86@kernel.org, linux-riscv@lists.infradead.org, Mike Rapoport , Ingo Molnar , Michael Kerrisk , Arnd Bergmann , James Bottomley , Hagen Paul Pfeifer , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org, Andrew Morton , Rick Edgecombe Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Fri, Nov 13, 2020 at 02:06:56PM +0000, Matthew Wilcox wrote: > On Tue, Nov 10, 2020 at 05:14:39PM +0200, Mike Rapoport wrote: > > diff --git a/mm/Kconfig b/mm/Kconfig > > index c89c5444924b..d8d170fa5210 100644 > > --- a/mm/Kconfig > > +++ b/mm/Kconfig > > @@ -884,4 +884,7 @@ config ARCH_HAS_HUGEPD > > config MAPPING_DIRTY_HELPERS > > bool > > > > +config SECRETMEM > > + def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED > > So I now have to build this in, whether I want it or not? Why wouldn't anybody want this nice feature? ;-) Now, seriously, I hesitated a lot about having a prompt here, but in the end I've decided to go without it. The added footprint is not so big, with x86 defconfig it's less than 8K and with distro (I've checked with Fedora) config the difference is less than 1k because they anyway have CMA=y. As this is "security" feature, disros most probably would have this enabled anyway, and I believe users that will see something like "Allow hiding memory from the kernel" will hit Y there. -- Sincerely yours, Mike. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 75DDBC2D0E4 for ; Sun, 15 Nov 2020 08:47:29 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 213DE223FB for ; Sun, 15 Nov 2020 08:47:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="eweHV11G"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mvUrkC8D" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 213DE223FB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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=merlin.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=nRN6pxvrQrUZH0vvjo4kIG3H/Xx15xHvs/WGVhypqXg=; b=eweHV11GcIwsFICuHXze+oh62 5OLUxaxs+FvxArBqIcYx4JKFvAs08NOYRsRrDVWkx3U2WThtIPj7eN6q7UrBhoa2ZjV8OQk3IlDag basfLodlsoirUkKc4gdkDZ6zVkJlnVh52SuaI6lDW/dKsfoxJYhkfv7I87zm19ac46/5B49Xmps/I X+jUKTDF8RrdU3w/kGHWneBzwNu/dM5m9VTCNK4El2i2KAKPUPFUZEJ5hv/ffDPc4VNqkQ3PZbaq7 lF0rHMSysgtY9ZER/665aMCUvjxFShFoFBPCNJA+RqVCQcxraGwWDxchxBjUAEivzjl/X3RxKBizW W3OkQy67w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1keDfb-00019I-Ug; Sun, 15 Nov 2020 08:45:59 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1keDfY-00017v-1Y; Sun, 15 Nov 2020 08:45:57 +0000 Received: from kernel.org (unknown [77.125.7.142]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AC352223FB; Sun, 15 Nov 2020 08:45:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605429954; bh=I2e6oiG56Ipc+LYVEf48Tzpdu9e5X2SPeAjMkXGJ+FY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mvUrkC8DbWSBeGtX5LmBQbQw3erYKhs5cOaKJid6GDJMPM7nXXubIxoNcBB3oGNe7 rCwIs49LamtntTc1amgIjfXRya2sb8UfoqlV6jooN7E3J+NN/S80wRZL4M8ZXWanKD tXrCqT3L+M5TGE/FDZPfoLrZTF0AQQmH6gi3Hxpk= Date: Sun, 15 Nov 2020 10:45:39 +0200 From: Mike Rapoport To: Matthew Wilcox Subject: Re: [PATCH v8 4/9] mm: introduce memfd_secret system call to create "secret" memory areas Message-ID: <20201115084539.GU4758@kernel.org> References: <20201110151444.20662-1-rppt@kernel.org> <20201110151444.20662-5-rppt@kernel.org> <20201113140656.GG17076@casper.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201113140656.GG17076@casper.infradead.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201115_034556_224767_7D615350 X-CRM114-Status: GOOD ( 17.75 ) 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: Mark Rutland , David Hildenbrand , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, "H. Peter Anvin" , Christopher Lameter , Shuah Khan , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Will Deacon , x86@kernel.org, linux-riscv@lists.infradead.org, Mike Rapoport , Ingo Molnar , Michael Kerrisk , Arnd Bergmann , James Bottomley , Hagen Paul Pfeifer , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org, Andrew Morton , Rick Edgecombe Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Nov 13, 2020 at 02:06:56PM +0000, Matthew Wilcox wrote: > On Tue, Nov 10, 2020 at 05:14:39PM +0200, Mike Rapoport wrote: > > diff --git a/mm/Kconfig b/mm/Kconfig > > index c89c5444924b..d8d170fa5210 100644 > > --- a/mm/Kconfig > > +++ b/mm/Kconfig > > @@ -884,4 +884,7 @@ config ARCH_HAS_HUGEPD > > config MAPPING_DIRTY_HELPERS > > bool > > > > +config SECRETMEM > > + def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED > > So I now have to build this in, whether I want it or not? Why wouldn't anybody want this nice feature? ;-) Now, seriously, I hesitated a lot about having a prompt here, but in the end I've decided to go without it. The added footprint is not so big, with x86 defconfig it's less than 8K and with distro (I've checked with Fedora) config the difference is less than 1k because they anyway have CMA=y. As this is "security" feature, disros most probably would have this enabled anyway, and I believe users that will see something like "Allow hiding memory from the kernel" will hit Y there. -- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel