From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751407AbdCZDZG (ORCPT ); Sat, 25 Mar 2017 23:25:06 -0400 Received: from mail.kernel.org ([198.145.29.136]:41016 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751252AbdCZDZE (ORCPT ); Sat, 25 Mar 2017 23:25:04 -0400 From: Masami Hiramatsu To: linux-kernel@vger.kernel.org, Ingo Molnar Cc: Peter Zijlstra , Thomas Gleixner , "H . Peter Anvin" , Ananth N Mavinakayanahalli , Anil S Keshavamurthy , "David S . Miller" , Andrey Ryabinin , mhiramat@kernel.org Subject: [RFC PATCH tip/master 0/8] kprobes/x86: Make kprobes instruction buffers read-only Date: Sun, 26 Mar 2017 12:23:38 +0900 Message-Id: <149049860802.5373.14864980110354664466.stgit@devbox> X-Mailer: git-send-email 2.9.3 User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, This series tries to make kprobes instruction buffers read-only pages. Since those buffers are used for trampoline code, those are a part of "text area" and it should be marked as ro for avoiding unexpected modification. And this actually fix a warning rodata sanity check. This change requires changing the kprobe-booster at first because it can modify the instruction buffer to add a jump while resuming from single-stepping. Of course after we make the buffer readonly, we may not be able to modify it while probing. So, at first this series checks the current bootable instructions and fixes a missed instruction (call far), modifies can_boost to use x86 instruction decoder, and inserts "booster" jump while preparing instruction buffer instead of resuming from single-stepping. At last, it makes the buffers for kprobes and optprobe readonly. This series also has some cleanup patches related to above changes. --- Masami Hiramatsu (8): kprobes/x86: Fix not to boost call far instruction kprobes/x86: Fix the description of __copy_instruction() kprobes/x86: Use instruction decoder for booster kprobes/x86: Do not modify singlestep buffer while resuming kprobes/x86: Make boostable flag boolean kprobes/x86: Set kprobes pages readonly kprobes/x86: Use probe_kernel_read instead of memcpy kprobes/x86: Consolidate insn decoder users for copying code arch/x86/include/asm/kprobes.h | 7 +- arch/x86/kernel/kprobes/common.h | 4 + arch/x86/kernel/kprobes/core.c | 143 +++++++++++++++++++------------------- arch/x86/kernel/kprobes/ftrace.c | 2 - arch/x86/kernel/kprobes/opt.c | 13 +++ 5 files changed, 86 insertions(+), 83 deletions(-) -- Masami Hiramatsu (Linaro)