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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 77CCEC433ED for ; Mon, 19 Apr 2021 22:00:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5145160E0C for ; Mon, 19 Apr 2021 22:00:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240782AbhDSWA7 (ORCPT ); Mon, 19 Apr 2021 18:00:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:46908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229863AbhDSWA7 (ORCPT ); Mon, 19 Apr 2021 18:00:59 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 EA20D613AA; Mon, 19 Apr 2021 22:00:26 +0000 (UTC) Date: Mon, 19 Apr 2021 18:00:24 -0400 From: Steven Rostedt To: Jiri Olsa Cc: Andrii Nakryiko , Jiri Olsa , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Networking , bpf , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Daniel Xu , Jesper Brouer , Toke =?UTF-8?B?SMO4aWxhbmQtSsO4cmdlbnNlbg==?= , Viktor Malik Subject: Re: [PATCHv2 RFC bpf-next 0/7] bpf: Add support for ftrace probe Message-ID: <20210419180024.02d53b91@gandalf.local.home> In-Reply-To: References: <20210413121516.1467989-1-jolsa@kernel.org> <20210415111002.324b6bfa@gandalf.local.home> <20210415141831.7b8fbe72@gandalf.local.home> <20210415142120.7427b4bd@gandalf.local.home> <20210415193032.34aec994@oasis.local.home> 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: netdev@vger.kernel.org On Mon, 19 Apr 2021 22:51:46 +0200 Jiri Olsa wrote: > now, it looks like the fgraph_ops entry callback does not have access > to registers.. once we have that, we could store arguments for the exit > callback and have all in place.. could this be added? ;-) Sure. The only problem is that we need to do this carefully to not break all the architectures that support function graph tracing. For function tracing, I usually add "CONFIG_HAVE_..." configs that state if the architecture supports some ftrace feature, and if it does it can use a different callback prototype. But it does get messy. Ideally, I would love to go and update all architectures to support all features, but that requires understanding the assembly of all those architectures :-p To test that I don't break other archs, I usually just support x86_64 and leave x86_32 behind. I mean, who cares about x86_32 anymore ;-) -- Steve