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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 4B7E1C388F9 for ; Sat, 7 Nov 2020 14:10:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0EB3720719 for ; Sat, 7 Nov 2020 14:10:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604758212; bh=/cmrteONQ5VrT8WyKBVaKDbW134CqlhPulNPF5/0dso=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=SxovA1nmZPwA8RGwbyg2NV7jNla92FOqDV61Ec2cmNfAMeTvBeKX5eIs1u7Cdr/Q1 q6JxsM8OmVnouczk/mKRFau+Tw7K7ssklQkCUOJO9TWNWjTcJbRBHtV7nhjrxL4c3r EIO32TwVuI+JtR0SCZYv6QtTvUz1z1CvQaSMwMwk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728197AbgKGOKL (ORCPT ); Sat, 7 Nov 2020 09:10:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:58028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727298AbgKGOKK (ORCPT ); Sat, 7 Nov 2020 09:10:10 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 85415206ED; Sat, 7 Nov 2020 14:10:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604758210; bh=/cmrteONQ5VrT8WyKBVaKDbW134CqlhPulNPF5/0dso=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=C1vtH8OWUTlC3Kc+wD5ydbY9tuS/mLXRzaK0ijA+9rdpImqoNperxV1ln7AxHgNfP ySBtRhE5h9p4G47cSlqW5XFjFU4+UlKLBqrrRSQwNkeAccXv+4YrvjPlIC7DCdnfVc xGV+KxNKyNq4RJOZI73ztEWJKCLj0TD2tlqgVwqo= Date: Sat, 7 Nov 2020 15:10:06 +0100 From: Greg Kroah-Hartman To: Vineet Gupta Cc: "stable@vger.kernel.org" , "linux-snps-arc@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Waldemar Brodkorb Subject: Re: [PATCH] Revert "ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE" Message-ID: <20201107141006.GB28983@kroah.com> References: <20201020021957.1260521-1-vgupta@synopsys.com> <9cec26bd-6839-b90d-9bda-44936457e883@synopsys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9cec26bd-6839-b90d-9bda-44936457e883@synopsys.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 06, 2020 at 08:27:44PM +0000, Vineet Gupta wrote: > Hi Stable Team, > > On 10/19/20 7:19 PM, Vineet Gupta wrote: > > This reverts commit 00fdec98d9881bf5173af09aebd353ab3b9ac729. > > (but only from 5.2 and prior kernels) > > > > The original commit was a preventive fix based on code-review and was > > auto-picked for stable back-port (for better or worse). > > It was OK for v5.3+ kernels, but turned up needing an implicit change > > 68e5c6f073bcf70 "(ARC: entry: EV_Trap expects r10 (vs. r9) to have > > exception cause)" merged in v5.3 which itself was not backported. > > So to summarize the stable backport of this patch for v5.2 and prior > > kernels is busted and it won't boot. > > > > The obvious solution is backport 68e5c6f073bcf70 but that is a pain as > > it doesn't revert cleanly and each of affected kernels (so far v4.19, > > v4.14, v4.9, v4.4) needs a slightly different massaged varaint. > > So the easier fix is to simply revert the backport from 5.2 and prior. > > The issue was not a big deal as it would cause strace to sporadically > > not work correctly. > > > > Waldemar Brodkorb first reported this when running ARC uClibc regressions > > on latest stable kernels (with offending backport). Once he bisected it, > > the analysis was trivial, so thx to him for this. > > > > Reported-by: Waldemar Brodkorb > > Bisected-by: Waldemar Brodkorb > > Cc: stable # 5.2 and prior > > Signed-off-by: Vineet Gupta > > Can this revert be please applied to 4.19 and older kernels for the next cycle. > > Or is there is a procedural issue given this revert is not in mainline. I've > described the issue in detail above so if there's a better/desirable way of > reverting it from backports, please let me know. THis is fine, sorry, it's just in a backlog of lots of stable patches... We will get to it soon. thanks, greg k-h