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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D002C433F5 for ; Wed, 6 Apr 2022 15:00:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235360AbiDFPB5 (ORCPT ); Wed, 6 Apr 2022 11:01:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235443AbiDFPBt (ORCPT ); Wed, 6 Apr 2022 11:01:49 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A54BA2102A8; Wed, 6 Apr 2022 04:46:11 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 078E6B8225B; Wed, 6 Apr 2022 11:44:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC284C385A3; Wed, 6 Apr 2022 11:44:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649245443; bh=NxeimgFKXbpME/i8GbhGeyomnmNXOaXJQCJ3je+GzkE=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=Ib9hdNGGYkrCQaXv+Wa1skJOD2XxfidXfz1pqcxFsyXCCzxmlx4Q3Iv3zMczs0oKa FQe0DNtq44xqgLu38lKgQlYFw3Ij795WPlkExr4Ro8+jAkTyioR9A9BMIhk91q9J+R QabboGRB4qGh2cnlhPER2Onwrw5Q/VSEu3RqX41pc3se7y9sXoIwT3O2RDYpgi6Z8l CNg8ObMUpX+4Zv4u9Bk/mM3AAvhsbWPbeyNFTQSoXvExtLE6vXtR5ciAv6Yh1XrMBw O1wSUjRp0lg0zIDtO2k54+FomdDRCXHT/n5i7rQLiEC8H5aU6PZ2AIaF9+r4Ajgm4Q iJs2PmQtEfQ7A== Received: by mail-ot1-f52.google.com with SMTP id x8-20020a9d6288000000b005b22c373759so1519896otk.8; Wed, 06 Apr 2022 04:44:03 -0700 (PDT) X-Gm-Message-State: AOAM533HDRs+1aVPN4Log4NvSw4lyrz6mEWkVlB0UFC7qu6e/WVj85nf l1xJEwSD2btu6yqjLqvrcQk+d5RhKHpwj0Adn7Q= X-Google-Smtp-Source: ABdhPJwgIpRNFG6qcoAVBzxDEl4cLier8VLEXG9sCYAAHpDzoTvzxVWsFwYD+jTe+LzI54KUubxiebLt/6VhtToTqKA= X-Received: by 2002:a05:6830:2e7:b0:5b2:68c1:182a with SMTP id r7-20020a05683002e700b005b268c1182amr2838747ote.71.1649245442897; Wed, 06 Apr 2022 04:44:02 -0700 (PDT) MIME-Version: 1.0 References: <20220405070339.801210740@linuxfoundation.org> <20220405070402.195698649@linuxfoundation.org> In-Reply-To: From: Ard Biesheuvel Date: Wed, 6 Apr 2022 13:43:51 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 5.15 746/913] ARM: ftrace: avoid redundant loads or clobbering IP To: Sasha Levin Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, "Steven Rostedt (Google)" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, 6 Apr 2022 at 13:23, Sasha Levin wrote: > > On Tue, Apr 05, 2022 at 12:01:19PM +0200, Ard Biesheuvel wrote: > >On Tue, 5 Apr 2022 at 11:54, Greg Kroah-Hartman > > wrote: > >> > >> From: Ard Biesheuvel > >> > >> [ Upstream commit d11967870815b5ab89843980e35aab616c97c463 ] > >> > >> Tweak the ftrace return paths to avoid redundant loads of SP, as well as > >> unnecessary clobbering of IP. > >> > >> This also fixes the inconsistency of using MOV to perform a function > >> return, which is sub-optimal on recent micro-architectures but more > >> importantly, does not perform an interworking return, unlike compiler > >> generated function returns in Thumb2 builds. > >> > >> Let's fix this by popping PC from the stack like most ordinary code > >> does. > >> > >> Signed-off-by: Ard Biesheuvel > >> Reviewed-by: Steven Rostedt (Google) > >> Signed-off-by: Sasha Levin > > > >Please drop all the 32-bit ARM patches authored by me from the stable > >queues except the ones that have fixes tags. These are highly likely > > I can drop you from future selections as well. > Yes, please. Just disregard all of my patches, unless they have a fixes or cc:stable, or someone suggests them explicitly. > >to cause an explosion of regressions, and they should have never been > >selected, as I don't remember anyone proposing these for stable. > > They were proposed by the bot last week > (https://lore.kernel.org/lkml/20220330115005.1671090-22-sashal@kernel.org/). > Yeah, we should really not be using a bot for that.