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=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 028E7C433B4 for ; Fri, 7 May 2021 14:54:03 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 9608D613ED for ; Fri, 7 May 2021 14:54:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9608D613ED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com 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=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc: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=kDauTuXdVTU+Wh2gz7e2EpWCVaNlir31GeIcUaL09rg=; b=GF3ey38EiqLvWQst5IEVUAcum GL9BwTTojxAcYIouWzbXVXt02o/MOE5i+0hZbfv9J0UwAWPb8vwKFcvr0LSTl8EiMhSjGnfmUJWMq YGX8iIWwzpPI8He9/kNJNzv/RI3/Xrw80hsABgW8Aph18wf/7BrBhETSzI6yE1QqBp4fszMm43VMT jao5rR4U28QHlJgREr3zDqE1Yz1nWmDzr4z7FC6GMSmWyVBqxuYaVHN+eEE5WvZH5hvQ1/wm3UY3Z GkZsyh4w1zxEjKa3DNI9TDt+Ud0M1CujwgBtYYYjtOTJdmBrV2wqAZ5AzCjA5nlL/Epkg1CRY/WDK dfVUAa53Q==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lf1q7-007Mzi-A5; Fri, 07 May 2021 14:52:27 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lf1q5-007Mz1-49 for linux-arm-kernel@desiato.infradead.org; Fri, 07 May 2021 14:52:25 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5tiGeaHhu4yIDUOM6XnLrKEexTpNeI24rCB8BbvXyxc=; b=1mNuCurN2PaZYem9y3T94p2ea3 UBFpMs3Yd31oez8tJq8/dAhyeuTVNnzV8ySiTYtTIbORf6Ve4ySwQ2b7+IGVYsCxcT9akv9J9udvt lTC/g5pyjETQWrTC3Ey8faXLn6C0kDhbmYNyAxQI8rkVo6n5jgKrWvj9DUo88yztlRmwFYEIdiblT WyHEYCBCxa6b5bfceT9tumy6jB3UvbFD6DoKvB8WCpL4v/ptGuYR8WubkDugd1eI7vunSD8vVsCED cfxb5VW1bl3+kM2tYqA5YM5ewr4i2qyENQhuaV3ONJkFuUqPAPTF9bf6mzsUoY+9zaFi/TKbP8/+5 +uzJJ0FA==; Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lf1q2-006wPp-9h for linux-arm-kernel@lists.infradead.org; Fri, 07 May 2021 14:52:23 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 22F4C61075; Fri, 7 May 2021 14:52:17 +0000 (UTC) Date: Fri, 7 May 2021 15:52:15 +0100 From: Catalin Marinas To: Peter Collingbourne Cc: Vincenzo Frascino , Will Deacon , Evgenii Stepanov , Andrey Konovalov , linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org Subject: Re: [PATCH] arm64: mte: initialize RGSR_EL1.SEED in __cpu_setup Message-ID: <20210507145215.GC26528@arm.com> References: <20210507033725.1479129-1-pcc@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210507033725.1479129-1-pcc@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210507_075222_416964_1DDEE063 X-CRM114-Status: GOOD ( 11.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Thu, May 06, 2021 at 08:37:25PM -0700, Peter Collingbourne wrote: > A valid implementation choice for the ChooseRandomNonExcludedTag() > pseudocode function used by IRG is to behave in the same way as with > GCR_EL1.RRND=0. This would mean that RGSR_EL1.SEED is used as an LFSR > which must have a non-zero value in order for IRG to properly produce > pseudorandom numbers. However, RGSR_EL1 is reset to an UNKNOWN value > on soft reset and thus may reset to 0. Therefore we must initialize > RGSR_EL1.SEED to a non-zero value in order to ensure that IRG behaves > as expected. > > Signed-off-by: Peter Collingbourne > Cc: stable@vger.kernel.org Rather than a generic cc stable that goes all the way to 4.4, please add: Fixes: 3b714d24ef17 ("arm64: mte: CPU feature detection and initial sysreg configuration") Cc: # 5.10.x Thanks. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel