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 3AAC2C4332F for ; Wed, 6 Apr 2022 01:06:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1839945AbiDFBG2 (ORCPT ); Tue, 5 Apr 2022 21:06:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1457875AbiDEQyN (ORCPT ); Tue, 5 Apr 2022 12:54:13 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B7D6326E9; Tue, 5 Apr 2022 09:52:15 -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 sin.source.kernel.org (Postfix) with ESMTPS id EC474CE1BE1; Tue, 5 Apr 2022 16:52:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B165C385A0; Tue, 5 Apr 2022 16:52:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649177532; bh=poRB8B2FuBtCIIZNBvi5x128WVA6VtVUiXU61lbpEBY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TG6JZgYEg7jQWabdXKKhw9T+Mlw6+RPQ0sgOsFVe9vRQmqpIcDWKq8onF0ySaaHNX r/lYiXkiFnuXcfMLS00lQpn/insSguaeHkwCOw0ycjwkbmK0IZL6zV8+CcEBxPVKMw j0c6N9/JuW76fcgMpF9wHudOxTRqkc8AoWHzPyP0= Date: Tue, 5 Apr 2022 18:52:09 +0200 From: Greg Kroah-Hartman To: Ard Biesheuvel Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, "Steven Rostedt (Google)" , Sasha Levin Subject: Re: [PATCH 5.15 746/913] ARM: ftrace: avoid redundant loads or clobbering IP Message-ID: References: <20220405070339.801210740@linuxfoundation.org> <20220405070402.195698649@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > to cause an explosion of regressions, and they should have never been > selected, as I don't remember anyone proposing these for stable. >From what I can tell, that is only this commit. I'll go drop it from all trees, thanks. greg k-h