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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D446CC433E0 for ; Thu, 6 Aug 2020 12:23:48 +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 B79ED22D05 for ; Thu, 6 Aug 2020 12:23:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="EuRCxZV1"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="q44JM/Mh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B79ED22D05 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name 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=6j7pV8c/QsOe45MckrfYSOuwYpRg2z+6n/KO0+nhf6w=; b=EuRCxZV1JliWUMKAs7MY8ie/g EU+rJApqsBrqcKL0SgnfYyzt6G/8HvMiLG+yM+FcJ1GQ4t5G6LbqYqQfgAmmfRHajy0QCKU9gUCyW /fK7v0V0Ox7u1u0WR4h53iKj/OskSQY1GFisrp4jxCHZyVBrgu0cNOucHaV1AnRIAxYBYewXoihAd bFTQGTG5pJqOZ5Ighu1iir4OFF8q0NNjJ9iMhp3MpYE7QD+EjVXPOpp59wSWgINwuAQzi2dApFUut 9SHOljf1hdUACIipl+wlOz10UBMsy+XR5dH9jUAAUppzoVkrOtQKXXddkONJiQuuvZWLTFgnt13UF 26dx0yMsQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k3d7r-0007p3-Jz; Thu, 06 Aug 2020 10:27:55 +0000 Received: from mail-lj1-x243.google.com ([2a00:1450:4864:20::243]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k3d7n-0007nX-HH for linux-arm-kernel@lists.infradead.org; Thu, 06 Aug 2020 10:27:53 +0000 Received: by mail-lj1-x243.google.com with SMTP id t23so27647177ljc.3 for ; Thu, 06 Aug 2020 03:27:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=kMBgMZhsaHkiYpNXe6mnulxBmErGl6mZVT718X/hP1s=; b=q44JM/MhPtGS1X8CEtdPT8jY1IsznRmL/EUJCRVKZ0SQjpJuKmiF3MRSg0V201k6/0 7wdleRwGXgcpS6GBcJQn3aN4+K1pHDGZuvFRDvTF9APAIhXb+a2xl9Jp+eur4UHwQKOG a+RLO7aCLHiHjNUkqDHv3KHpAByqNpYKygFYVYfjG2rDRNZ1boVJjHid9G6QxHXMRDHj lxu6G5SWy3EMKBtlkZJxRZeLycn9DXYVVNUnw64xSNl8FhKmMBKmB/5GaDUrg6bknGVy 69EcKcUZE3qqrUPWzoTffaHacemMJWCOZb/G6QEBjYa8rAKMuVSkNGFwC876gdtvvS/j Xp6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=kMBgMZhsaHkiYpNXe6mnulxBmErGl6mZVT718X/hP1s=; b=Ta6fjyZpMbNaxA9+BIwpzfDRdpQgjonSda36zZKmKR7CK+pq2+lsFivRy43DBu9S/v FtIjQJmVzlP3zYI3pZNy5qULRfM5KKR/38GUjnB2NlrbCRSuXWwNzFbmlHuvYhAPyqu9 ndNAya15Ajku9ykIkrKnZhUcLW68RGiOkrQAQJExkdkgS4GSFL8wyi8R8YUUjZnJgaiS SglmB9EEWfQoxy13ljlL+2GOx2hgOqMfjzRA0BQdbjaESFh7Q741+ArDDrlmqFWLhL0y prT7FPhN8Cewlyl1xuFIZrm3qNE6ryz9KTdCYf8Qqc03BkXrqCcEtXIUYRRJ2oDuajwr 0Pjw== X-Gm-Message-State: AOAM531b8CTbXTyhE/WQjHP0JIKrBKKZzqmDZRQnK7BdsxvHwalDn4Nb 21sSShyqrk6s8EGNtQTfFzTXjA== X-Google-Smtp-Source: ABdhPJwKs0kOBphzk4nhXY72GuBZVVKvwfIRMs8kMWmC7io4Zo82tk1RHZ72Ob2Qcz50sTYcK1DvmA== X-Received: by 2002:a05:651c:201b:: with SMTP id s27mr3653296ljo.468.1596709669841; Thu, 06 Aug 2020 03:27:49 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id h18sm2208204ljk.7.2020.08.06.03.27.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Aug 2020 03:27:49 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 80A47102E1B; Thu, 6 Aug 2020 13:27:57 +0300 (+03) Date: Thu, 6 Aug 2020 13:27:57 +0300 From: "Kirill A. Shutemov" To: Mike Rapoport Subject: Re: [PATCH v3 3/6] mm: introduce memfd_secret system call to create "secret" memory areas Message-ID: <20200806102757.7vobcaewdukr2xdl@box> References: <20200804095035.18778-1-rppt@kernel.org> <20200804095035.18778-4-rppt@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200804095035.18778-4-rppt@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200806_062752_297186_760A2041 X-CRM114-Status: GOOD ( 20.11 ) 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 , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, "H. Peter Anvin" , Christopher Lameter , Idan Yaniv , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Will Deacon , x86@kernel.org, Matthew Wilcox , Mike Rapoport , Ingo Molnar , Michael Kerrisk , Arnd Bergmann , James Bottomley , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org, Andrew Morton 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 Tue, Aug 04, 2020 at 12:50:32PM +0300, Mike Rapoport wrote: > From: Mike Rapoport > > Introduce "memfd_secret" system call with the ability to create memory > areas visible only in the context of the owning process and not mapped not > only to other processes but in the kernel page tables as well. > > The user will create a file descriptor using the memfd_secret() system call > where flags supplied as a parameter to this system call will define the > desired protection mode for the memory associated with that file > descriptor. Currently there are two protection modes: > > * exclusive - the memory area is unmapped from the kernel direct map and it > is present only in the page tables of the owning mm. > * uncached - the memory area is present only in the page tables of the > owning mm and it is mapped there as uncached. I'm not sure why flag for exclusive mode is needed. It has to be default. And if you want uncached on top of that set the flag. What am I missing? -- Kirill A. Shutemov _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel