Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753720AbcD1Upr (ORCPT ); Thu, 28 Apr 2016 16:45:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37161 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753657AbcD1Upn (ORCPT ); Thu, 28 Apr 2016 16:45:43 -0400 From: Josh Poimboeuf To: Jessica Yu , Jiri Kosina , Miroslav Benes , Ingo Molnar , Peter Zijlstra , Michael Ellerman , Heiko Carstens Cc: live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, Vojtech Pavlik , Jiri Slaby , Petr Mladek , Chris J Arges , Andy Lutomirski Subject: [RFC PATCH v2 16/18] livepatch: store function sizes Date: Thu, 28 Apr 2016 15:44:47 -0500 Message-Id: <361d707752ac660ab88c9539d6d28cbe8685e415.1461875890.git.jpoimboe@redhat.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1744 Lines: 59 For the consistency model we'll need to know the sizes of the old and new functions to determine if they're on the stacks of any tasks. Signed-off-by: Josh Poimboeuf --- include/linux/livepatch.h | 3 +++ kernel/livepatch/core.c | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index 9ba26c5..c38c694 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -37,6 +37,8 @@ * @old_addr: the address of the function being patched * @kobj: kobject for sysfs resources * @stack_node: list node for klp_ops func_stack list + * @old_size: size of the old function + * @new_size: size of the new function * @patched: the func has been added to the klp_ops list */ struct klp_func { @@ -56,6 +58,7 @@ struct klp_func { unsigned long old_addr; struct kobject kobj; struct list_head stack_node; + unsigned long old_size, new_size; bool patched; }; diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index f28504d..aa3dbdf 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -577,6 +577,22 @@ static int klp_init_object_loaded(struct klp_patch *patch, &func->old_addr); if (ret) return ret; + + ret = kallsyms_lookup_size_offset(func->old_addr, + &func->old_size, NULL); + if (!ret) { + pr_err("kallsyms size lookup failed for '%s'\n", + func->old_name); + return -ENOENT; + } + + ret = kallsyms_lookup_size_offset((unsigned long)func->new_func, + &func->new_size, NULL); + if (!ret) { + pr_err("kallsyms size lookup failed for '%s' replacement\n", + func->old_name); + return -ENOENT; + } } return 0; -- 2.4.11