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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 45139C5DF61 for ; Thu, 7 Nov 2019 12:12:50 +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 0FFCA21882 for ; Thu, 7 Nov 2019 12:12:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QLzKnlVZ"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sirena.org.uk header.i=@sirena.org.uk header.b="v574dL0B" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0FFCA21882 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: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:In-Reply-To:References: List-Owner; bh=pUja1QiG/LHU1rnN7D88O1Es80cxczlvR1oFHTJHW4w=; b=QLzKnlVZr/s3wQ UbTQ1wYcQGVhnP4FI8Nx2flCQ4kiN47N69PYYTxRj6KnG5O4aok6AfdIaiMyR13NRW66JB2SZm1dL dOcGYBF3iEet4HbTVqE8yfyHplMJjAc02/MD6+/ItqqgmHyXvZayf7I5CXr2qS6gzyHUTlmYQkaHo 4I8/p3Xx1E95glYV0hx/SOb1BiL7jUiDZU/X3VUFLF8tjC5dszKW+vgsrU++GeFHocMxnwLR//y3p XN8UE2Iq4lNx3KGdSCnvW720TsShSU8bCAAdZhpdeVxjbFsewLVXfop96s3ti3vGLNFwXKD4sWzYb TO9vwKzswyG3QpEdMWxw==; 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 1iSgee-0000Ux-NR; Thu, 07 Nov 2019 12:12:48 +0000 Received: from heliosphere.sirena.org.uk ([172.104.155.198]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iSgeb-0000U6-Ud for linux-arm-kernel@lists.infradead.org; Thu, 07 Nov 2019 12:12:47 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sirena.org.uk; s=20170815-heliosphere; h=Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=mqab7UDvfBiNsFyyYLe+hloVEA9Ce+SF33HE2FH0Aw0=; b=v574dL0BaUIne7goIh34RUj/8 qHCOtqDv4rVC3R46Tqg/KmcqnUqOpb+RIbMMFvIeKa0Erds62PmfKmXkfbU0IInLi+A+OLFR3Rf7U F/7LMZCgzA/ZPsg9MQFnGO83/eILO9ipEUZUR62/vBxfUza7dl6hz8GgwriPOXBWLseb4=; Received: from cpc102320-sgyl38-2-0-cust46.18-2.cable.virginm.net ([82.37.168.47] helo=ypsilon.sirena.org.uk) by heliosphere.sirena.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iSgeZ-0004H4-DZ; Thu, 07 Nov 2019 12:12:43 +0000 Received: by ypsilon.sirena.org.uk (Postfix, from userid 1000) id A363627431AF; Thu, 7 Nov 2019 12:12:42 +0000 (GMT) From: Mark Brown To: Catalin Marinas , Will Deacon Subject: [PATCH] arm64: kaslr: Print warning if KASLR is disabled due to lack of seed Date: Thu, 7 Nov 2019 12:12:41 +0000 Message-Id: <20191107121241.8458-1-broonie@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191107_041245_987274_241273B1 X-CRM114-Status: GOOD ( 12.35 ) 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 Brown , 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 It seems to be a relatively common system integration error for system integrators and administrators to enable KASLR in their configuration but not provide the seed at runtime, sometimes due to that breaking at some later point after it is initially enabled. Since KASLR is not announced at boot time unless it forces on KPTI this can lead to users incorrectly believing their system has the feature enabled when in fact it does not, and if they notice the problem the lack of any diagnostics makes it harder to understand the problem. Provide a warning message to assist in these situations. Signed-off-by: Mark Brown --- arch/arm64/kernel/kaslr.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c index 416f537bf614..c2ba5e783ada 100644 --- a/arch/arm64/kernel/kaslr.c +++ b/arch/arm64/kernel/kaslr.c @@ -98,8 +98,10 @@ u64 __init kaslr_early_init(u64 dt_phys) * Retrieve (and wipe) the seed from the FDT */ seed = get_kaslr_seed(fdt); - if (!seed) + if (!seed) { + pr_warn("No seed available for KASLR, disabling\n"); return 0; + } /* * Check if 'nokaslr' appears on the command line, and -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel