Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422780AbaD3OcS (ORCPT ); Wed, 30 Apr 2014 10:32:18 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:52338 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759223AbaD3Oav (ORCPT ); Wed, 30 Apr 2014 10:30:51 -0400 From: Jiri Slaby To: linux-kernel@vger.kernel.org Cc: jirislaby@gmail.com, Vojtech Pavlik , Michael Matz , Jiri Kosina , Jiri Slaby , Udo Seidel Subject: [RFC 06/16] kgr: add Documentation Date: Wed, 30 Apr 2014 16:30:39 +0200 Message-Id: <1398868249-26169-7-git-send-email-jslaby@suse.cz> X-Mailer: git-send-email 1.9.2 In-Reply-To: <1398868249-26169-1-git-send-email-jslaby@suse.cz> References: <1398868249-26169-1-git-send-email-jslaby@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a text provided by Udo and polished. Signed-off-by: Jiri Slaby Cc: Udo Seidel --- Documentation/kgr.txt | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/kgr.txt diff --git a/Documentation/kgr.txt b/Documentation/kgr.txt new file mode 100644 index 000000000000..5b62415641cf --- /dev/null +++ b/Documentation/kgr.txt @@ -0,0 +1,26 @@ +Live Kernel Patching with kGraft +-------------------------------- + +Written by Udo Seidel +Based on the Blog entry by Vojtech Pavlik + +April 2014 + +kGraft's developement was started by the SUSE Labs. kGraft builds on +technologies and ideas that are already present in the kernel: ftrace +and its mcount-based reserved space in function headers, the +INT3/IPI-NMI patching also used in jumplabels, and RCU-like update of +code that does not require stopping the kernel. For more information +about ftrace please checkout the Documentation shipped with the kernel +or search for howtos and explanations on the Internet. + +A kGraft patch is a kernel module and fully relies on the in-kernel +module loader to link the new code with the kernel. Thanks to all +that, the design can be nicely minimalistic. + +While kGraft is, by choice, limited to replacing whole functions and +constants they reference, this does not limit the set of code patches +that can be applied significantly. kGraft offers tools to assist in +creating the live patch modules, identifying which functions need to +be replaced based on a patch, and creating the patch module source +code. They are located in /tools/kgraft/. -- 1.9.2 -- 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/