Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754494AbcCYTgW (ORCPT ); Fri, 25 Mar 2016 15:36:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42907 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754087AbcCYTgS (ORCPT ); Fri, 25 Mar 2016 15:36:18 -0400 From: Josh Poimboeuf To: Jiri Kosina , Jessica Yu , Miroslav Benes Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Vojtech Pavlik Subject: [RFC PATCH v1.9 11/14] livepatch: store function sizes Date: Fri, 25 Mar 2016 14:34:58 -0500 Message-Id: <033beaef425f0e243c5be9a616f0b7e72a860adb.1458933243.git.jpoimboe@redhat.com> In-Reply-To: References: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 25 Mar 2016 19:36:18 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1739 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 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 6d45dc7..dd5db74 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 beaf263..b0fd31d 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -540,6 +540,22 @@ 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; -- 2.4.3