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 1528AC636D4 for ; Wed, 15 Feb 2023 09:24:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233840AbjBOJYE (ORCPT ); Wed, 15 Feb 2023 04:24:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230225AbjBOJYC (ORCPT ); Wed, 15 Feb 2023 04:24:02 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 987AD222D1 for ; Wed, 15 Feb 2023 01:24:00 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8Ax59ivpOxj6d8AAA--.1548S3; Wed, 15 Feb 2023 17:23:59 +0800 (CST) Received: from localhost.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Bxjb6upOxjWsczAA--.34752S2; Wed, 15 Feb 2023 17:23:58 +0800 (CST) From: Qing Zhang To: Huacai Chen , Oleg Nesterov , WANG Xuerui Cc: Jiaxun Yang , loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v3 0/3] LoongArch: Add hardware breakpoints/watchpoints support Date: Wed, 15 Feb 2023 17:23:55 +0800 Message-Id: <20230215092358.30368-1-zhangqing@loongson.cn> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: AQAAf8Bxjb6upOxjWsczAA--.34752S2 X-CM-SenderInfo: x2kd0wptlqwqxorr0wxvrqhubq/ X-Coremail-Antispam: 1Uk129KBjvJXoWxZry8uw1DKF1fKF4fAr13urg_yoW5Aw4DpF ZIkrn5Kr4DKrW3Zwsxtw48ur1fGF1xCrW2q3W2y34aywnFqr1Fqrn5Kr9Fqay5A34rJ340 qF1rWw4Fga4DAaUanT9S1TB71UUUUjUqnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b3AYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1l n4kS14v26r1Y6r17M2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6x ACxx1l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1q6rW5McIj6I8E 87Iv67AKxVW8JVWxJwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82 IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1l4IxYO2xFxVAFwI0_Jrv_JF1lx2Iq xVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r 126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Gr0_Xr1lIxAIcVC0I7IYx2IY 6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67 AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuY vjxU4AhLUUUUU Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use perf framework to manage hardware instruction and data breakpoints. LoongArch defines hardware watchpoint functions for instruction fetch and load/store operations, after the software configures hardware watchpoints for instruction fetch and load/store operations. The processor hardware will monitor the access address of the instruction fetch and load/store operation, and will trigger the exception of the watchpoint when it meets the conditions set by the watchpoint. The hardware monitoring points for instruction fetching and load/store operations each have a register for the overall configuration of all monitoring points, a register for recording the status of all monitoring points, and four registers required for configuration of each watchpoint individually. Watchpoint related control status register chapters: https://github.com/loongson/LoongArch-Documentation/releases/download/2022.08.12/ LoongArch-Vol1-v1.02-CN.pdf Initial version has the following limitations: - no support for virtualization Can be tested: e.g. 1. see samples/hw_breakpoint and register_wide_hw_breakpoint. 2. ptrace(PTRACE_SINGLESTEP/..., pid, NULL, NULL) 3. ptrace (PTRACE_SETREGSET, tid, ... , ...) TODO: - Add hardware breakpoints/watchpoints for gdb, kgdb Changes v1 -> v2: Suggested by Huacai: - Use irqentry_enter()/irqentry_exit() instead of exception_enter()/exception_exit(). - Add ptrace interface to expose hw-breakpoints to debuggers. - Use 2022-2023. - Some other changes. Changes v2 -> v3: Suggested by Jinyang: - get_num_brps/wrps, decode/encode_ctrl_reg which the function returns directly. - Remove irrelevant content from the first patch. - Use macros to avoid using magic values directly. - Add new arg to indicate it is breakpoint or watchpoint to avoid function coupling. - Remove redundant tab. - Modify the breakpoint/watchpoint_handler function type to void. - Some other changes. Qing Zhang (3): LoongArch: Add hardware breakpoints/watchpoints support LoongArch: Add ptrace single step support LoongArch: ptrace: expose hardware breakpoints to debuggers arch/loongarch/Kconfig | 1 + arch/loongarch/include/asm/hw_breakpoint.h | 145 ++++++ arch/loongarch/include/asm/loongarch.h | 32 +- arch/loongarch/include/asm/processor.h | 14 +- arch/loongarch/include/asm/ptrace.h | 2 + arch/loongarch/include/asm/switch_to.h | 1 + arch/loongarch/include/uapi/asm/ptrace.h | 9 + arch/loongarch/kernel/Makefile | 1 + arch/loongarch/kernel/hw_breakpoint.c | 544 +++++++++++++++++++++ arch/loongarch/kernel/process.c | 7 + arch/loongarch/kernel/ptrace.c | 484 ++++++++++++++++++ arch/loongarch/kernel/traps.c | 24 +- include/uapi/linux/elf.h | 2 + 13 files changed, 1245 insertions(+), 21 deletions(-) create mode 100644 arch/loongarch/include/asm/hw_breakpoint.h create mode 100644 arch/loongarch/kernel/hw_breakpoint.c -- 2.36.0