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 D903EC433F5 for ; Tue, 22 Mar 2022 02:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235505AbiCVCiP (ORCPT ); Mon, 21 Mar 2022 22:38:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235474AbiCVCiP (ORCPT ); Mon, 21 Mar 2022 22:38:15 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0004DDF6A; Mon, 21 Mar 2022 19:36:48 -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 B97ACB81B2A; Tue, 22 Mar 2022 02:36:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1C7DC340E8; Tue, 22 Mar 2022 02:36:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647916606; bh=H2U/BMwBsbk4jfUZgJSssTVvNeLCmKRIuki0dtsxEJ4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LD0mmBPGGcmYLHc2zdAZwSvK+uwqVzLTEgQU8CzJ0cKjxMVsjgi98LYP6LyRiDVFz vG6yoY3dyuiEV81m10c0iWsANnPFAsC7xlxV/s1pq+CyDvqM7U9cS38XU65bwcUpRM FBvbKM4V9Jzk076hunuQy9uJk0GbRUp8XX/29ros5wAeh12xnJKfA8PJf6dUh0x4EE SOnV6mirN2Lsb0DENfrdisTaCg/VOWYYypV7gcSaVlrT2nHWSD1jLqa3HoayakNX5I +nJ4oULTOsY7pWnIeM1RDIFypxqfu9VKgV6Kn6EdZ3N+TmnRR2peKEd2Di1oRg9DPt 75HogcuFPVLhw== Date: Tue, 22 Mar 2022 11:36:41 +0900 From: Masami Hiramatsu To: Alexei Starovoitov Cc: Linus Torvalds , David Miller , Daniel Borkmann , Peter Zijlstra , Steven Rostedt , Masami Hiramatsu , Jakub Kicinski , Andrii Nakryiko , Stephen Rothwell , Netdev , bpf , Kernel Team Subject: Re: pull-request: bpf-next 2022-03-21 Message-Id: <20220322113641.763885257f741ac5c0cb2c06@kernel.org> In-Reply-To: References: <20220321224608.55798-1-alexei.starovoitov@gmail.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; 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: bpf@vger.kernel.org Hi Linus and Alexei, At first, sorry about this issue. I missed to Cc'ed to arch maintainers. On Mon, 21 Mar 2022 17:31:28 -0700 Alexei Starovoitov wrote: > On Mon, Mar 21, 2022 at 4:59 PM Linus Torvalds > wrote: > > > > On Mon, Mar 21, 2022 at 4:11 PM Alexei Starovoitov > > wrote: > > > > > > Did you look at the code? > > > In particular: > > > https://lore.kernel.org/bpf/164735286243.1084943.7477055110527046644.stgit@devnote2/ > > > > > > it's a copy paste of arch/x86/kernel/kprobes/core.c > > > > > > How is it "bad architecture code" ? > > > > It's "bad architecture code" because the architecture maintainers have > > made changes to check ENDBR in the meantime. > > > > So it used to be perfectly fine. It's not any longer - and the > > architecture maintainers were clearly never actually cc'd on the > > changes, so they didn't find out until much too late. Let me retry porting fprobe on top of ENDBR things and confirm with arch maintainers. > > Not denying that missing cc was an issue. > > We can drop just arch patches: > rethook: x86: Add rethook x86 implementation > arm64: rethook: Add arm64 rethook implementation > powerpc: Add rethook support > ARM: rethook: Add rethook arm implementation > > or everything including Jiri's work on top of it. > Which would be a massive 27 patches. > > We'd prefer the former, of course. > Later during the merge window we can add a single > 'rethook: x86' patch that takes endbr into account, > so that multi-kprobe feature will work on x86. > For the next merge window we can add other archs. > Would that work? BTW, As far as I can see the ENDBR things, the major issue on fprobe is that the ftrace'ed ip address will be different from the symbol address (even) on x86. That must be ensured to work before merge. Let me check it on Linus's tree at first. Thank you, -- Masami Hiramatsu