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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 11EF0C4332F for ; Tue, 20 Dec 2022 20:14:21 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Nc78D1DxLz3cC1 for ; Wed, 21 Dec 2022 07:14:20 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=BNIgEyD2; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=139.178.84.217; helo=dfw.source.kernel.org; envelope-from=ebiggers@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=BNIgEyD2; dkim-atps=neutral Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Nc7745gchz2xWg for ; Wed, 21 Dec 2022 07:13:20 +1100 (AEDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A6E606159E; Tue, 20 Dec 2022 20:13:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2276C433EF; Tue, 20 Dec 2022 20:13:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671567196; bh=Gv7ILarnqG6VXDv1zDoq4dXMcpli2fdU3fYWtrhD7CU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BNIgEyD2b/kwnXbaR5eP2QBP6UOPAvQD/zXFajZWt6RT74gXhm2s6OW4N4KlIDYfC Wxj/cb6C47OFZnLUTyNjRVTrtsstBCz34eSTcFuSh8xOdIJfvtKJ0/S3YG8qtuZO+h LVw/GM01Blb4idgGSfUfT/5N9ejTRXvuE5Mw1vrfiD3+t4k4Xbat5lWBMHcLkl/46L MZPNmMJsegfvf0rTSEXW5sH0CokCzOrUgUPmh+IzXUqga3I07y9uao2n9w8QT5IQiS MZzetOEpR2Sv47PnKm1OJ3NaodmMfXpe4ekWd75YuDtjccDI1UPYcXzuqMblveH5rR DHTVp2kedMNHw== Date: Tue, 20 Dec 2022 20:13:14 +0000 From: Eric Biggers To: Christophe Leroy Subject: Re: [PATCH v12 0/6] implement getrandom() in vDSO Message-ID: References: <20221212185347.1286824-1-Jason@zx2c4.com> <86cfa465-2485-ff24-16f5-9014e25a0e98@csgroup.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <86cfa465-2485-ff24-16f5-9014e25a0e98@csgroup.eu> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Florian Weimer , "Jason A. Donenfeld" , Arnd Bergmann , Jann Horn , Carlos O'Donell , "linux-api@vger.kernel.org" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "patches@lists.linux.dev" , "linux-crypto@vger.kernel.org" , Adhemerval Zanella Netto , Greg Kroah-Hartman , Christian Brauner , "tglx@linutronix.de" , "linuxppc-dev@lists.ozlabs.org" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Dec 20, 2022 at 05:17:52PM +0000, Christophe Leroy wrote: > Hi Jason, > > Le 12/12/2022 à 19:53, Jason A. Donenfeld a écrit : > > Changes v11->v12: > > ---------------- > > - In order to avoid mlock()ing pages, and the related rlimit and fork > > inheritance issues there, Introduce VM_DROPPABLE to prevent swapping > > while meeting the cache-like requirements of vDSO getrandom(). > > > > This has some tenticles in mm/ and arch/x86/ code, so I've marked the > > two patches for that as still RFC, while the rest of the series is not > > RFC. > > > > - Mandate that opaque state blobs don't straddle page boundaries, so > > that VM_DROPPABLE can work on page-level granularity rather than > > allocation-level granularity. > > > > - Add compiler barriers to vDSO getrandom() to prevent theoretical > > reordering potential. > > > > - Initialize the trials loop counter in the chacha test. > > I would have liked to give it a try on powerpc, but the series > conflicts. I tried both on v6.1 and on linus/master from now: > Same here, I can't figure out how to apply this series. It would help if people always used the --base option to git format-patch... - Eric