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