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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 67E13C83000 for ; Tue, 28 Apr 2020 14:54:01 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 36DA4206D9 for ; Tue, 28 Apr 2020 14:54:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="OJGYWkNR"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="SbNi47LS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36DA4206D9 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+infradead-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=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qgEWrahbO4oQJ64mMrOFmwcRS7bcdJnlVavilyDMbLI=; b=OJGYWkNRaqgE1l JipyLYss19VgWcyjTI4xXNn6sNlkLqRhUiwPMzTqFuQbo7TAbxS9Bp5QLtXbVjULYc9y5BvKu8KCZ fjhWgAFN4zOmA5aeroQUbxjaoydYsQpVKNlP2n8A3Z6cxV9uDfNutva+y0JK+lzgDs3FLB1iMmRWR XRJBflwHmYKs34jagbP17qmfPKfsylK4E2w5l7vyArR44uyKiL0+mX5GXUEAzv3WMwpJaiGBphQX0 B7fFGsGVNrkqdrB1CZWdTwvkKm2ogKnL05kdHMVRWNtgS4mELqNtk9sUw8qr6jmqrf3Eew6l8YuAe mqCrjTKGoMwV7Zay2V2Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jTRcV-0005GH-UB; Tue, 28 Apr 2020 14:53:59 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jTRYe-0008UN-Eg for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2020 14:50:04 +0000 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7770C206D6; Tue, 28 Apr 2020 14:49:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588085399; bh=KQVhaFJwaQDI1LQ4GB7LyZpVuA9l1lrKtbwaO9ObaOo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SbNi47LSVdZKZiCKx5OXieBgFz0DUjpnCJw+d8ky+EBGf/9hMTjEH5FQdSwfpa4dz dVo8xHQgEcPIUhqEjBh0wR0hxCG1DDXBQZg/IaeTxSJQM/iBVtvBqUrSyeB4Lgof7O wIjlNWqIjUTtMeeXcGO5/k0pZ+DkMhnzJRVdj1OE= From: Will Deacon To: George Spelvin Subject: Re: [PATCH v2] arm64: kexec_file: Avoid temp buffer for RNG seed Date: Tue, 28 Apr 2020 15:49:39 +0100 Message-Id: <158807855142.208424.6865350866606582490.b4-ty@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200330173801.GA9199@SDF.ORG> References: <202003281643.02SGhMtr029198@sdf.org> <20200330133701.GA10633@willie-the-truck> <20200330173801.GA9199@SDF.ORG> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200428_075000_529013_B4884DDD X-CRM114-Status: UNSURE ( 9.32 ) X-CRM114-Notice: Please train this message. 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: lkml@sdf.org, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, Hsin-Yi Wang , Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 30 Mar 2020 17:38:01 +0000, George Spelvin wrote: > After using get_random_bytes(), you want to wipe the buffer > afterward so the seed remains secret. > > In this case, we can eliminate the temporary buffer entirely. > fdt_setprop_placeholder() returns a pointer to the property value > buffer, allowing us to put the random data directly in there without > using a temporary buffer at all. Faster and less stack all in one. Applied to arm64 (for-next/misc), thanks! [1/1] arm64: kexec_file: Avoid temp buffer for RNG seed https://git.kernel.org/arm64/c/99ee28d99607 Cheers, -- Will https://fixes.arm64.dev https://next.arm64.dev _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel