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 2E213C43334 for ; Mon, 11 Jul 2022 23:56:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229914AbiGKX4A (ORCPT ); Mon, 11 Jul 2022 19:56:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229477AbiGKX4A (ORCPT ); Mon, 11 Jul 2022 19:56:00 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 179592BB3F; Mon, 11 Jul 2022 16:55:59 -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 A5041B8100E; Mon, 11 Jul 2022 23:55:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90A9BC34115; Mon, 11 Jul 2022 23:55:54 +0000 (UTC) Date: Mon, 11 Jul 2022 19:55:52 -0400 From: Steven Rostedt To: Song Liu Cc: , , , , , , , , , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , live-patching@vger.kernel.org Subject: Re: [PATCH v2 bpf-next 0/5] ftrace: host klp and bpf trampoline together Message-ID: <20220711195552.22c3a4be@gandalf.local.home> In-Reply-To: <20220602193706.2607681-1-song@kernel.org> References: <20220602193706.2607681-1-song@kernel.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org I just realized that none of the live kernel patching folks are Cc'd on this thread. I think they will care much more about this than I do. -- Steve On Thu, 2 Jun 2022 12:37:01 -0700 Song Liu wrote: > Changes v1 => v2: > 1. Fix build errors for different config. (kernel test robot) > > Kernel Live Patch (livepatch, or klp) and bpf trampoline are important > features for modern systems. This set allows the two to work on the same > kernel function as the same time. > > live patch uses ftrace with IPMODIFY, while bpf trampoline use direct > ftrace. Existing policy does not allow the two to attach to the same kernel > function. This is changed by fine tuning ftrace IPMODIFY policy, and allows > one non-DIRECT IPMODIFY ftrace_ops and one non-IPMODIFY DIRECT ftrace_ops > on the same kernel function at the same time. Please see 3/5 for more > details on this. > > Note that, one of the constraint here is to let bpf trampoline use direct > call when it is not working on the same function as live patch. This is > achieved by allowing ftrace code to ask bpf trampoline to make changes. > > Jiri Olsa (1): > bpf, x64: Allow to use caller address from stack > > Song Liu (4): > ftrace: allow customized flags for ftrace_direct_multi ftrace_ops > ftrace: add modify_ftrace_direct_multi_nolock > ftrace: introduce FTRACE_OPS_FL_SHARE_IPMODIFY > bpf: trampoline: support FTRACE_OPS_FL_SHARE_IPMODIFY > > arch/x86/net/bpf_jit_comp.c | 13 +- > include/linux/bpf.h | 8 ++ > include/linux/ftrace.h | 79 +++++++++++ > kernel/bpf/trampoline.c | 109 +++++++++++++-- > kernel/trace/ftrace.c | 269 +++++++++++++++++++++++++++++++----- > 5 files changed, 424 insertions(+), 54 deletions(-) > > -- > 2.30.2