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 32646C4332F for ; Thu, 17 Nov 2022 20:00:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240450AbiKQUAV (ORCPT ); Thu, 17 Nov 2022 15:00:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234246AbiKQUAT (ORCPT ); Thu, 17 Nov 2022 15:00:19 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C5117EC9C; Thu, 17 Nov 2022 12:00:18 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 0F3A96205B; Thu, 17 Nov 2022 20:00:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 722D9C433C1; Thu, 17 Nov 2022 20:00:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1668715217; bh=vO+cKwGnnt7Ikp4K63ZOyB2XNYmenlQEdQ2QOJjZGLs=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=qBYjZa/IMlM5KHeE09wABdhBZYEwPpjSjJIewLnsQOK2jagLXDzJKNAC+8P0TGMXB aHGKpChuj12Gwa7Bf4xXECgPo8xYZys0D7zAFVnUYPqyq+GfMzHbgUY7AL5WMud7Ig ACvYjH5wAkDAYx2409RaAYKs88aLxCkw0dL02JMhF2v4T2hV5Mrj94QELuDjvy9BoI UcJe8WHHheCZtWrkr0AHL9Y2RctZqIuX2fvaCpTrLGZFvSN7olSLrkR+FcOV1IFu0V RkuT9dRd8U1xbpV8pu7/ya50NWOGz3iRdQzSLENEj0ITSYTyZkF5BQfoeKTx/R7D/U DSTTSk6NLM3xQ== Received: by mail-ej1-f52.google.com with SMTP id t25so7795802ejb.8; Thu, 17 Nov 2022 12:00:17 -0800 (PST) X-Gm-Message-State: ANoB5pktOUx3aYSim57QAhG8Asd4qyqns6vuS9rw2x+7LzrDI+2YO3K6 KZ6EagFccW8GTIHZCjISBKMEq+rbejbpvUHO8eg= X-Google-Smtp-Source: AA0mqf6SNJLDD3oiqBQCmMYdAYbreHZsfuDK2kTU00718Bq5Y5pcgY1A6dEu0CdLovuJ4lmnGI/Lx90ew7Kr9kt8xFM= X-Received: by 2002:a17:906:2645:b0:781:d0c1:4434 with SMTP id i5-20020a170906264500b00781d0c14434mr3379349ejc.756.1668715215682; Thu, 17 Nov 2022 12:00:15 -0800 (PST) MIME-Version: 1.0 References: <20221114114344.18650-1-jirislaby@kernel.org> <20221114114344.18650-41-jirislaby@kernel.org> In-Reply-To: <20221114114344.18650-41-jirislaby@kernel.org> From: Song Liu Date: Thu, 17 Nov 2022 12:00:03 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 40/46] x86/livepatch, lto: Disable live patching with gcc LTO To: "Jiri Slaby (SUSE)" Cc: linux-kernel@vger.kernel.org, Andi Kleen , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , live-patching@vger.kernel.org, Andi Kleen , Martin Liska , Jiri Slaby Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 14, 2022 at 3:48 AM Jiri Slaby (SUSE) wrote: > > From: Andi Kleen > > It is not supported by gcc 12 so far, so it causes compiler "sorry" > messages. > > Other than the compiler support, there shouldn't be any barriers for > live patching LTOed kernels, although it might be more difficult to > create patches for larger functions. A loosely related question: does livepatch work with CLANG LTO? AFAICT, kpatch-build doesn't support it. But the kernel side should work just fine? Thanks, Song [...]