From patchwork Mon Aug 7 06:48:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13343129 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 7B9DFEB64DD for ; Mon, 7 Aug 2023 06:48:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229793AbjHGGsd (ORCPT ); Mon, 7 Aug 2023 02:48:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229484AbjHGGsc (ORCPT ); Mon, 7 Aug 2023 02:48:32 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 571571B5; Sun, 6 Aug 2023 23:48:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E7893614DD; Mon, 7 Aug 2023 06:48:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0513C433C7; Mon, 7 Aug 2023 06:48:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691390910; bh=dbLyRNDw66rtMco9Z3macc8TBfHCjdg7YPc5a5Rum2s=; h=From:To:Cc:Subject:Date:From; b=ESMIgjjLZ6TVNFPZDm+7nkFhf40Hl1mivSWSwCUSdT5ajD52CJDQYYbPKvKYVONZb p2tJb3bHYV0AEgIaG5AKhm2gIfRUM4o0GPZYLyC11VjWhjCzgZghvZbQxZPRXnUJxl A8IqYz6BHjoQdO7U0R8ICJVFUEvJiSJiCim5fjGqXVR9boCHx2GjOdXxqmgthNpPel NU40+dugZoH9tZs6Ll74Qow1RFULjnX1LhOGO4r2RnFqMnoHUyURwkrRkmDWmTjlFX KS12lgGVH39v4Vfn5kvTVJswUByK3Jt3jK8cqkP/pIA5eDqxb4ATN39/nr3WHQeMZO dGS2CqPUGz/ag== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Peter Zijlstra , Thomas Gleixner Subject: [RFC PATCH v2 0/6] bpf: fprobe: rethook: Use ftrace_regs instead of pt_regs Date: Mon, 7 Aug 2023 15:48:24 +0900 Message-Id: <169139090386.324433.6412259486776991296.stgit@devnote2> X-Mailer: git-send-email 2.34.1 User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org Hi, Here is the 2nd version of RFC series to use ftrace_regs instead of pt_regs. But this includes the generic part and minimum modifications of arch dependent code. (e.g. not including rethook for arm64.) This series is based on the discussion at https://lore.kernel.org/all/20230801112036.0d4ee60d@gandalf.local.home/ This version includes 1 patch to expose ftrace_regs. so - Simply replace pt_regs in fprobe_entry_handler with ftrace_regs. - Expose ftrace_regs even if CONFIG_FUNCTION_TRACER=n. - Replace pt_regs in rethook and fprobe_exit_handler with ftrace_regs. This introduce a new HAVE_PT_REGS_COMPAT_FTRACE_REGS which means ftrace_regs is just a wrapper of pt_regs (except for arm64, other architectures do this) - Update fprobe-events to use ftrace_regs natively. - Introduce ftrace_partial_regs(). (This changes ARM64 which needs a custom implementation) - Update bpf multi-kprobe handler use ftrace_partial_regs(). Florent, feel free to add your rethook for arm64, but please do not remove kretprobe trampoline yet. It is another discussion point. We may be possible to use ftrace_regs for kretprobe by ftrace_partial_regs() but kretprobe allows nest probe. (maybe we can skip that case?) This series can also be found below branch. https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/log/?h=topic/fprobe-ftrace-regs Thank you, --- Masami Hiramatsu (Google) (6): fprobe: Use fprobe_regs in fprobe entry handler tracing: Expose ftrace_regs regardless of CONFIG_FUNCTION_TRACER fprobe: rethook: Use fprobe_regs in fprobe exit handler and rethook tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS ftrace: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled arch/Kconfig | 1 + arch/arm64/include/asm/ftrace.h | 11 ++++++ arch/loongarch/Kconfig | 1 + arch/s390/Kconfig | 1 + arch/x86/Kconfig | 1 + arch/x86/kernel/rethook.c | 9 +++-- include/linux/fprobe.h | 4 +- include/linux/ftrace.h | 56 ++++++++++++++++++----------- include/linux/rethook.h | 11 +++--- kernel/kprobes.c | 9 ++++- kernel/trace/Kconfig | 9 ++++- kernel/trace/bpf_trace.c | 14 +++++-- kernel/trace/fprobe.c | 8 ++-- kernel/trace/rethook.c | 16 ++++---- kernel/trace/trace_fprobe.c | 76 ++++++++++++++++++++++++--------------- kernel/trace/trace_probe_tmpl.h | 2 + lib/test_fprobe.c | 10 +++-- samples/fprobe/fprobe_example.c | 4 +- 18 files changed, 154 insertions(+), 89 deletions(-) -- Masami Hiramatsu (Google)