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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 F210FC43441 for ; Tue, 13 Nov 2018 19:58:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB59B223C8 for ; Tue, 13 Nov 2018 19:58:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB59B223C8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=packi.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730732AbeKNF57 (ORCPT ); Wed, 14 Nov 2018 00:57:59 -0500 Received: from mail.binarylogic.ch ([88.198.23.72]:47876 "EHLO mail.binarylogic.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725748AbeKNF57 (ORCPT ); Wed, 14 Nov 2018 00:57:59 -0500 Received: from fortknox.localdomain (unknown [192.168.122.1]) by mail.binarylogic.ch (Postfix) with ESMTP id 49195DF386; Tue, 13 Nov 2018 20:58:18 +0100 (CET) From: =?UTF-8?q?Patrick=20St=C3=A4hlin?= To: linux-riscv@lists.infradead.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?Patrick=20St=C3=A4hlin?= , Palmer Dabbelt , Albert Ou Subject: [RFC/RFT 0/2] RISC-V: kprobes/kretprobe support Date: Tue, 13 Nov 2018 20:58:02 +0100 Message-Id: <20181113195804.22825-1-me@packi.ch> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, this is first version of kprobes/kretprobe support for RISC-V. Most of the code is based on arm64 but obviously without the single-step functionality. It will insert a C.EBREAK instruction that is later being captured. The only instruction supported at the moment is C.ADDISP16 as this sets-up the stack frames for all the functions I've tested. I've tested this on QEMU with multiple CPUs but don't have any real hardware available for testing, and from experience that's when things start breaking. The plan is to expand compressed instructions to full ones and simulate those to reduce the decoding overhead per intercepted call. Please let me know if you have any objections to path I've chosen and which instructions you absolutely need for a first version. To enable this you need the following defines: CONFIG_FUNCTION_TRACER=y CONFIG_KPROBES=y CONFIG_MODULES=y The CONFIG_FUNCTION_TRACER is not strictly needed but makes testing easier using debugfs. After that, any example documented in Documentation/trace/kprobetrace.rst should work. Patrick Stählin (2): RISC-V: Implement ptrace regs and stack API RISC-V: kprobes/kretprobe support arch/riscv/Kconfig | 6 +- arch/riscv/include/asm/kprobes.h | 30 ++ arch/riscv/include/asm/probes.h | 26 ++ arch/riscv/include/asm/ptrace.h | 34 ++ arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/probes/Makefile | 3 + arch/riscv/kernel/probes/decode-insn.c | 38 ++ arch/riscv/kernel/probes/decode-insn.h | 23 + arch/riscv/kernel/probes/kprobes.c | 401 ++++++++++++++++++ arch/riscv/kernel/probes/kprobes_trampoline.S | 91 ++++ arch/riscv/kernel/probes/simulate-insn.c | 33 ++ arch/riscv/kernel/probes/simulate-insn.h | 8 + arch/riscv/kernel/ptrace.c | 99 +++++ arch/riscv/kernel/traps.c | 13 +- arch/riscv/mm/fault.c | 28 +- 15 files changed, 828 insertions(+), 6 deletions(-) create mode 100644 arch/riscv/include/asm/probes.h create mode 100644 arch/riscv/kernel/probes/Makefile create mode 100644 arch/riscv/kernel/probes/decode-insn.c create mode 100644 arch/riscv/kernel/probes/decode-insn.h create mode 100644 arch/riscv/kernel/probes/kprobes.c create mode 100644 arch/riscv/kernel/probes/kprobes_trampoline.S create mode 100644 arch/riscv/kernel/probes/simulate-insn.c create mode 100644 arch/riscv/kernel/probes/simulate-insn.h -- 2.17.1