From patchwork Mon Mar 1 11:30:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jinyang He X-Patchwork-Id: 12109509 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 3F22AC433DB for ; Mon, 1 Mar 2021 11:31:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1308E64E31 for ; Mon, 1 Mar 2021 11:31:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233784AbhCALbi (ORCPT ); Mon, 1 Mar 2021 06:31:38 -0500 Received: from mail.loongson.cn ([114.242.206.163]:50514 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S233717AbhCALbX (ORCPT ); Mon, 1 Mar 2021 06:31:23 -0500 Received: from loongson.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9AxmdQ50Dxgz20SAA--.23162S2; Mon, 01 Mar 2021 19:30:01 +0800 (CST) From: Jinyang He To: Thomas Bogendoerfer Cc: Tiezhu Yang , Xuefeng Li , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org Subject: [PATCH RFC] MIPS: livepatch: Add LIVEPATCH basic code Date: Mon, 1 Mar 2021 19:30:01 +0800 Message-Id: <1614598201-17858-1-git-send-email-hejinyang@loongson.cn> X-Mailer: git-send-email 2.1.0 X-CM-TRANSID: AQAAf9AxmdQ50Dxgz20SAA--.23162S2 X-Coremail-Antispam: 1UD129KBjvJXoWxGr1kGw1Utw18Cw45KFyxGrg_yoW5Kr17pF Z8A3Z5Gr4Uur93GFya9w1Y9ry3Jas5WrWakFyxW34Fvas8Xa48Xrn7Krn8AryUXrWkta4x uFyYgr1UCr42vaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkq14x267AKxVWUJVW8JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xII jxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVW8JVWxJwAm72CE4IkC6x0Yz7v_Jr0_Gr 1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxkIecxEwVAFwVW8KwCF 04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r 18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vI r41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr 1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAI cVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUUAhltUUUUU== X-CM-SenderInfo: pkhmx0p1dqwqxorr0wxvrqhubq/ Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Add the basic code of livepatch. livepatch is temporarily unavailable. Two core functions are missing, one is DYNAMIC_FTRACE_WITH_REGS, and another is save_stack_trace_tsk_reliable(). `Huang Pei ` is doing for ftrace. He will use `-fpatchable-function-entry` to achieve more complete ftrace. save_stack_trace_tsk_reliable() currently has difficulties. This function may be improved in the future, but that seems to be a long time away. This is also the reason for delivering this RFC. Hope to get any help. Signed-off-by: Jinyang He --- arch/mips/Kconfig | 1 + arch/mips/include/asm/livepatch.h | 28 ++++++++++++++++++++++++++++ arch/mips/include/asm/thread_info.h | 1 + arch/mips/kernel/mcount.S | 9 +++++++++ 4 files changed, 39 insertions(+) create mode 100644 arch/mips/include/asm/livepatch.h diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 47715cb..8ef92dd 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -478,6 +478,7 @@ config MACH_LOONGSON64 select CEVT_R4K select CPU_HAS_WB select FORCE_PCI + select HAVE_LIVEPATCH select ISA select I8259 select IRQ_MIPS_CPU diff --git a/arch/mips/include/asm/livepatch.h b/arch/mips/include/asm/livepatch.h new file mode 100644 index 0000000..26e1212 --- /dev/null +++ b/arch/mips/include/asm/livepatch.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * livepatch.h - mips-specific Kernel Live Patching Core + */ + +#ifndef _ASM_MIPS_LIVEPATCH_H +#define _ASM_MIPS_LIVEPATCH_H + +#include +#include + +static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip) +{ + struct pt_regs *regs = ftrace_get_regs(fregs); + + regs->regs[31] = ip; +} + +#define klp_get_ftrace_location klp_get_ftrace_location +static inline unsigned long klp_get_ftrace_location(unsigned long faddr) +{ + unsigned long func_size, offset; + + kallsyms_lookup_size_offset(faddr, &func_size, &offset); + return ftrace_location_range(faddr, faddr + func_size); +} + +#endif diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h index e2c352d..1e78359 100644 --- a/arch/mips/include/asm/thread_info.h +++ b/arch/mips/include/asm/thread_info.h @@ -117,6 +117,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_UPROBE 6 /* breakpointed or singlestepping */ #define TIF_NOTIFY_SIGNAL 7 /* signal notifications exist */ #define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal() */ +#define TIF_PATCH_PENDING 10 /* pending live patching update */ #define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */ #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ #define TIF_NOHZ 19 /* in adaptive nohz mode */ diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index cff52b2..8bf4c6a 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -113,6 +113,15 @@ ftrace_stub: RETURN_BACK END(ftrace_caller) +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +NESTED(ftrace_regs_caller, PT_SIZE, ra) +/* ftrace_regs_caller body */ +#ifdef CONFIG_LIVEPATCH +/* Restore sp register */ +#endif + RETURN_BACK + END(ftrace_regs_caller) +#endif #else /* ! CONFIG_DYNAMIC_FTRACE */ NESTED(_mcount, PT_SIZE, ra)