From patchwork Tue Apr 5 09:33:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12801351 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6F1ECC433F5 for ; Tue, 5 Apr 2022 09:35:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=BLs473p5NqSme0ZQ9OzNvY4UNhMwAvkep+zUdc1D9eU=; b=HBwP0LVHg027ug l/pj5KYNOgfn610UOlhEVJq19r2bINp1kzCeL955BRRzUVU8AWat0FBzEe3gEQtOw7zdVRUnXkhtA z+4HN1dSCq7da03fUa3Rh0yTL/EWVBJ2DgNsc5NGL7fzkHJmRBzzpeGNgA9NjGCfgGky7b3esg7ae AS6eOIA6IfxX/ECDctx2z20Pj+GW29o9EG+fC3OkFci2Kl1+YFEFRF36cZxUItywVhfRRyfijynSB 0t5gBnb2FCJT2/itrfJaoc/cHgpZy2nt6gsCdwK0l4R1YBPcl5v8UGf0VpZ1wyUDgdq/7iW7guSI+ +Mr0fEQbEB09Z0w3sDQA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nbfZp-000RfQ-0K; Tue, 05 Apr 2022 09:34:17 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nbfZJ-000RJ6-Am for linux-arm-kernel@lists.infradead.org; Tue, 05 Apr 2022 09:33:47 +0000 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 42DDEB81C99; Tue, 5 Apr 2022 09:33:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E929C385A3; Tue, 5 Apr 2022 09:33:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649151222; bh=w3c3dan6gpCZQWuTtnrIYnuAybUzjLeMz5IygurzhmA=; h=From:To:Cc:Subject:Date:From; b=kgLWiwy+Hds+vv7jtXz+wCEvuU7WwMF35CGW4fvseZE4OkaO0Yd3mlyo8JYC5iVGO uFXJNuwwYiufvhErVF9rtRAmdMAf9QFUlIw7s4KblEqu3jiJThyfpg3Pdj8+c7iwdf UxPLbiN7DMMyuPqEy3eAHogBox9WvZxN+3hMUE1ZTkeIKi7wPxwfHpYUhsa5/P74Ip zvAM9pulY79SC6AVH6lREf4lMS+2cmOaJ9F38NH5jfAM9NjVU3vXQWjDxTkRizs/UN 55Sb9mjiEDKfpWKYqFrIicR2UZpZH1V8ZYuPdzHZ2hjvMM4KXrADZ6HtyUUoFAZsj/ H8FpvMavHtPzQ== From: Masami Hiramatsu To: Alexei Starovoitov , Alexei Starovoitov Cc: Daniel Borkmann , Shubham Bansal , Andrii Nakryiko , Masami Hiramatsu , bpf@vger.kernel.org, kernel-team@fb.com, Jiri Olsa , Steven Rostedt , "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" , linux-kernel@vger.kernel.org, Mark Rutland , Will Deacon , Ard Biesheuvel , Russell King , Catalin Marinas , linux-arm-kernel@lists.infradead.org Subject: [PATCH bpf 0/4] kprobes: rethook, ARM, arm64: Replace kretprobe trampoline with rethook Date: Tue, 5 Apr 2022 18:33:35 +0900 Message-Id: <164915121498.982637.12787715964983738566.stgit@devnote2> X-Mailer: git-send-email 2.25.1 User-Agent: StGit/0.19 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220405_023345_699157_C00F0FE4 X-CRM114-Status: GOOD ( 20.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello, Here is a series for replacing kretprobe trampoline with rethook on ARM/arm64. This series are applicable to bpf tree (not arm tree) because the basement patch is still only on that tree. Actually, this series includes a trivial bugfix for the arm unwinder to initialize an internal data structure([1/4]). This is not critical for stack trace, but required for rethook to find LR register on the stack. This also have an update for the rethook interface, which allows us to check the rethook_hook() failure ([2/4]). This is also required for the rethook on arm because unwinder is able to fail. The rest of patches are replacing kretprobe trampoline with rethook on ARM ([3/4]) and arm64 ([4/4]). Background: This rethook came from Jiri's request of multiple kprobe for bpf[1]. He tried to solve an issue that starting bpf with multiple kprobe will take a long time because bpf-kprobe will wait for RCU grace period for sync rcu events. Jiri wanted to attach a single bpf handler to multiple kprobes and he tried to introduce multiple-probe interface to kprobe. So I asked him to use ftrace and kretprobe-like hook if it is only for the function entry and exit, instead of adding ad-hoc interface to kprobes. For this purpose, I introduced the fprobe (kprobe like interface for ftrace) with the rethook (this is a generic return hook feature for fprobe exit handler)[2]. [1] https://lore.kernel.org/all/20220104080943.113249-1-jolsa@kernel.org/T/#u [2] https://lore.kernel.org/all/164191321766.806991.7930388561276940676.stgit@devnote2/T/#u The rethook is basically same as the kretprobe trampoline. I just made it decoupled from kprobes. Eventually, the all arch dependent kretprobe trampolines will be replaced with the rethook trampoline instead of cloning the code. When I port the rethook for all arch which supports kretprobe, the legacy kretprobe specific code (which is for CONFIG_KRETPROBE_ON_RETHOOK=n) will be removed eventually. BTW, the arm Clang support for rethook is for kretprobes only. fprobe and ftrace seems not working with Clang yet. Thank you, --- Masami Hiramatsu (4): ARM: unwind: Initialize the lr_addr field of unwind_ctrl_block rethook,fprobe,kprobes: Check a failure in the rethook_hook() ARM: rethook: Replace kretprobe trampoline with rethook arm64: rethook: Replace kretprobe trampoline with rethook arch/arm/Kconfig | 1 arch/arm/include/asm/stacktrace.h | 5 + arch/arm/kernel/stacktrace.c | 13 +-- arch/arm/kernel/unwind.c | 1 arch/arm/probes/Makefile | 1 arch/arm/probes/kprobes/core.c | 62 ------------ arch/arm/probes/rethook.c | 127 +++++++++++++++++++++++++ arch/arm64/Kconfig | 1 arch/arm64/include/asm/kprobes.h | 2 arch/arm64/include/asm/stacktrace.h | 2 arch/arm64/kernel/Makefile | 1 arch/arm64/kernel/probes/Makefile | 1 arch/arm64/kernel/probes/kprobes.c | 15 --- arch/arm64/kernel/probes/kprobes_trampoline.S | 86 ----------------- arch/arm64/kernel/rethook.c | 26 +++++ arch/arm64/kernel/rethook_trampoline.S | 87 +++++++++++++++++ arch/arm64/kernel/stacktrace.c | 9 +- arch/x86/kernel/rethook.c | 4 + include/linux/rethook.h | 4 - kernel/kprobes.c | 8 +- kernel/trace/fprobe.c | 5 + kernel/trace/rethook.c | 12 ++ 22 files changed, 285 insertions(+), 188 deletions(-) create mode 100644 arch/arm/probes/rethook.c delete mode 100644 arch/arm64/kernel/probes/kprobes_trampoline.S create mode 100644 arch/arm64/kernel/rethook.c create mode 100644 arch/arm64/kernel/rethook_trampoline.S -- Masami Hiramatsu (Linaro)