From patchwork Thu Aug 11 16:36:40 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Torsten Duwe X-Patchwork-Id: 9275621 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7BAD560780 for ; Thu, 11 Aug 2016 16:39:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6F02A28748 for ; Thu, 11 Aug 2016 16:39:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 63B902874A; Thu, 11 Aug 2016 16:39:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E113528748 for ; Thu, 11 Aug 2016 16:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932586AbcHKQhx (ORCPT ); Thu, 11 Aug 2016 12:37:53 -0400 Received: from verein.lst.de ([213.95.11.211]:42391 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932622AbcHKQgm (ORCPT ); Thu, 11 Aug 2016 12:36:42 -0400 Received: by newverein.lst.de (Postfix, from userid 2005) id 4CE7F68C44; Thu, 11 Aug 2016 18:36:40 +0200 (CEST) In-Reply-To: <20160811163451.D455C68C43@newverein.lst.de> References: <20160811163451.D455C68C43@newverein.lst.de> From: Torsten Duwe Subject: [PATCH v3 2/2] arm64: implement live patching To: Catalin Marinas , Will Deacon , takahiro.akashi@linaro.org, Jungseok Lee , Arnd Bergmann , Li Bin Cc: Steven Rostedt , Ingo Molnar , Christopher Li , Jiri Kosina , andrew.wafaa@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, linux-arch@vger.kernel.org, linux-sparse@vger.kernel.org Message-Id: <20160811163640.4CE7F68C44@newverein.lst.de> Date: Thu, 11 Aug 2016 18:36:40 +0200 (CEST) Sender: linux-sparse-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sparse@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP straightforward on top of FTRACE_WITH_REGS. Signed-off-by: Torsten Duwe --- arch/arm64/Kconfig | 3 +++ arch/arm64/include/asm/livepatch.h | 37 +++++++++++++++++++++++++++++++++++++ arch/arm64/kernel/entry-ftrace.S | 13 +++++++++++++ 3 files changed, 53 insertions(+) create mode 100644 arch/arm64/include/asm/livepatch.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 36a0e26..3aae199 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -80,6 +80,7 @@ config ARM64 select HAVE_GENERIC_DMA_COHERENT select HAVE_HW_BREAKPOINT if PERF_EVENTS select HAVE_IRQ_TIME_ACCOUNTING + select HAVE_LIVEPATCH select HAVE_MEMBLOCK select HAVE_MEMBLOCK_NODE_MAP if NUMA select HAVE_PATA_PLATFORM @@ -1042,4 +1043,6 @@ if CRYPTO source "arch/arm64/crypto/Kconfig" endif +source "kernel/livepatch/Kconfig" + source "lib/Kconfig" diff --git a/arch/arm64/include/asm/livepatch.h b/arch/arm64/include/asm/livepatch.h new file mode 100644 index 0000000..6b9a3d1 --- /dev/null +++ b/arch/arm64/include/asm/livepatch.h @@ -0,0 +1,37 @@ +/* + * livepatch.h - arm64-specific Kernel Live Patching Core + * + * Copyright (C) 2016 SUSE + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + */ +#ifndef _ASM_ARM64_LIVEPATCH_H +#define _ASM_ARM64_LIVEPATCH_H + +#include +#include + +#ifdef CONFIG_LIVEPATCH +static inline int klp_check_compiler_support(void) +{ + return 0; +} + +static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip) +{ + regs->pc = ip; +} +#endif /* CONFIG_LIVEPATCH */ + +#endif /* _ASM_ARM64_LIVEPATCH_H */ diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index 3ebe791..2108f0e 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -204,6 +204,9 @@ ENTRY(ftrace_caller) str x9, [sp, #S_LR] /* The program counter just after the ftrace call site */ str lr, [sp, #S_PC] +#if defined(CONFIG_LIVEPATCH) && defined(CONFIG_FUNCTION_GRAPH_TRACER) + mov x19,lr /* remember old return address */ +#endif /* The stack pointer as it was on ftrace_caller entry... */ add x29, sp, #S_FRAME_SIZE+16 /* ...is also our new FP */ str x29, [sp, #S_SP] @@ -219,6 +222,16 @@ ftrace_call: bl ftrace_stub +#if defined(CONFIG_LIVEPATCH) && defined(CONFIG_FUNCTION_GRAPH_TRACER) + /* Is the trace function a live patcher an has messed with + * the return address? + */ + ldr x9, [sp, #S_PC] + cmp x9, x19 /* compare with the value we remembered */ + /* to not call graph tracer's "call" mechanism twice! */ + b.ne ftrace_regs_return +#endif + #ifdef CONFIG_FUNCTION_GRAPH_TRACER .global ftrace_graph_call ftrace_graph_call: // ftrace_graph_caller();