From patchwork Mon Jun 27 15:17:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Torsten Duwe X-Patchwork-Id: 9200825 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 17F8A60757 for ; Mon, 27 Jun 2016 15:19:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0676C28412 for ; Mon, 27 Jun 2016 15:19:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id ED6F928598; Mon, 27 Jun 2016 15:19:08 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 952F728581 for ; Mon, 27 Jun 2016 15:19:08 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bHYIQ-0004Xv-OE; Mon, 27 Jun 2016 15:17:58 +0000 Received: from verein.lst.de ([213.95.11.211] helo=newverein.lst.de) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bHYI7-0004Gb-M8 for linux-arm-kernel@lists.infradead.org; Mon, 27 Jun 2016 15:17:43 +0000 Received: by newverein.lst.de (Postfix, from userid 2005) id B81C968D29; Mon, 27 Jun 2016 17:17:22 +0200 (CEST) From: Torsten Duwe In-Reply-To: <20160627151500.2247A68D20@newverein.lst.de> References: <20160627151500.2247A68D20@newverein.lst.de> Subject: [PATCH v2 2/2] arm64: implement live patching To: Catalin Marinas , Will Deacon , takahiro.akashi@linaro.org, Jungseok Lee , Arnd Bergmann , Li Bin Message-Id: <20160627151722.B81C968D29@newverein.lst.de> Date: Mon, 27 Jun 2016 17:17:22 +0200 (CEST) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160627_081740_112287_907A727A X-CRM114-Status: GOOD ( 13.95 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Christopher Li , Jiri Kosina , linux-kernel@vger.kernel.org, andrew.wafaa@arm.com, linux-sparse@vger.kernel.org, Ingo Molnar , Steven Rostedt , live-patching@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP On top of FTRACE_WITH_REGS and the klp changes that go into v4.7 this is straightforward. 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..cb5adf3 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..b166cbf 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.eq ftrace_regs_return +#endif + #ifdef CONFIG_FUNCTION_GRAPH_TRACER .global ftrace_graph_call ftrace_graph_call: // ftrace_graph_caller();