Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756512AbaJINBU (ORCPT ); Thu, 9 Oct 2014 09:01:20 -0400 Received: from mail7.hitachi.co.jp ([133.145.228.42]:60596 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751190AbaJINBL (ORCPT ); Thu, 9 Oct 2014 09:01:11 -0400 Subject: [PATCH ftrace/for-next v5 0/5] ftrace, kprobes: Introduce IPMODIFY flag for ftrace_ops to detect conflicts From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf Cc: Ingo Molnar , Namhyung Kim , Linux Kernel Mailing List , Ananth N Mavinakayanahalli Date: Thu, 09 Oct 2014 13:00:59 +0000 Message-ID: <20141009130059.4698.21616.stgit@kbuild-f20.novalocal> User-Agent: StGit/0.17-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, Here is the 5th version of the series of patches which introduces IPMODIFY flag for ftrace_ops to detect conflicts of ftrace users who can modify regs->ip in their handler. The previous version is here; https://lkml.org/lkml/2014/7/28/13 This version is basically an update of previous version to the latest ftrace tree, and adding a test code to selftest. Currently, only kprobes can change the regs->ip in the handler, but recently kpatch is also want to change it. Moreover, since the ftrace itself exported to modules, it might be considerable senario. Here we talked on github. https://github.com/dynup/kpatch/issues/47 To protect modified regs-ip from each other, this series introduces FTRACE_OPS_FL_IPMODIFY flag and ftrace now ensures the flag can be set on each function entry location. If there is someone who already reserve regs->ip on target function entry, ftrace_set_filter_ip or register_ftrace_function will return -EBUSY. Users must handle that. The ftrace_ops with IPMODIFY flag requires at least one entry for filter hash, and its notrace_hash must be empty, because the IPMODIFY action is very address sensitve and user must consider the ip address. The 3rd patch adds a special reservation of IPMODIFY on the jprobed address, since it is the only user who will change the regs->ip. Other kprobes do not change it anymore. Thank you, --- Masami Hiramatsu (5): kprobes/ftrace: Recover original IP if pre_handler doesn't change it ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict kprobes: Add IPMODIFY flag to kprobe_ftrace_ops kprobes: Set IPMODIFY flag only if the probe can change regs->ip kselftest,ftrace: Add ftrace IPMODIFY flag test Documentation/kprobes.txt | 12 + Documentation/trace/ftrace.txt | 5 + arch/x86/kernel/kprobes/ftrace.c | 9 + include/linux/ftrace.h | 16 ++ kernel/kprobes.c | 123 +++++++++++++-- kernel/trace/ftrace.c | 142 +++++++++++++++++ tools/testing/selftests/ftrace/Makefile | 11 + tools/testing/selftests/ftrace/ipmodify/Makefile | 15 ++ tools/testing/selftests/ftrace/ipmodify/ipmodify.c | 168 ++++++++++++++++++++ .../selftests/ftrace/ipmodify/run_ipmodify.sh | 6 + 10 files changed, 478 insertions(+), 29 deletions(-) create mode 100644 tools/testing/selftests/ftrace/ipmodify/Makefile create mode 100644 tools/testing/selftests/ftrace/ipmodify/ipmodify.c create mode 100644 tools/testing/selftests/ftrace/ipmodify/run_ipmodify.sh -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/