From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 996D3C43387 for ; Wed, 9 Jan 2019 12:43:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 606832173B for ; Wed, 9 Jan 2019 12:43:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731185AbfAIMnm (ORCPT ); Wed, 9 Jan 2019 07:43:42 -0500 Received: from mx2.suse.de ([195.135.220.15]:42628 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730145AbfAIMnj (ORCPT ); Wed, 9 Jan 2019 07:43:39 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 7F207AECF; Wed, 9 Jan 2019 12:43:37 +0000 (UTC) From: Petr Mladek To: Jiri Kosina , Josh Poimboeuf , Miroslav Benes Cc: Jason Baron , Joe Lawrence , Evgenii Shatokhin , live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, Petr Mladek Subject: [PATCH v15 01/11] livepatch: Change unsigned long old_addr -> void *old_func in struct klp_func Date: Wed, 9 Jan 2019 13:43:19 +0100 Message-Id: <20190109124329.21991-2-pmladek@suse.com> X-Mailer: git-send-email 2.13.7 In-Reply-To: <20190109124329.21991-1-pmladek@suse.com> References: <20190109124329.21991-1-pmladek@suse.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The address of the to be patched function and new function is stored in struct klp_func as: void *new_func; unsigned long old_addr; The different naming scheme and type are derived from the way the addresses are set. @old_addr is assigned at runtime using kallsyms-based search. @new_func is statically initialized, for example: static struct klp_func funcs[] = { { .old_name = "cmdline_proc_show", .new_func = livepatch_cmdline_proc_show, }, { } }; This patch changes unsigned long old_addr -> void *old_func. It removes some confusion when these address are later used in the code. It is motivated by a followup patch that adds special NOP struct klp_func where we want to assign func->new_func = func->old_addr respectively func->new_func = func->old_func. This patch does not modify the existing behavior. Suggested-by: Josh Poimboeuf Signed-off-by: Petr Mladek Acked-by: Miroslav Benes Acked-by: Joe Lawrence Acked-by: Alice Ferrazzi --- include/linux/livepatch.h | 4 ++-- kernel/livepatch/core.c | 6 +++--- kernel/livepatch/patch.c | 18 ++++++++++-------- kernel/livepatch/patch.h | 4 ++-- kernel/livepatch/transition.c | 4 ++-- 5 files changed, 19 insertions(+), 17 deletions(-) diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index aec44b1d9582..634e13876380 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -40,7 +40,7 @@ * @new_func: pointer to the patched function code * @old_sympos: a hint indicating which symbol position the old function * can be found (optional) - * @old_addr: the address of the function being patched + * @old_func: pointer to 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 @@ -77,7 +77,7 @@ struct klp_func { unsigned long old_sympos; /* internal */ - unsigned long old_addr; + void *old_func; struct kobject kobj; struct list_head stack_node; unsigned long old_size, new_size; diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 5b77a7314e01..cb59c7fb94cb 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -648,7 +648,7 @@ static void klp_free_object_loaded(struct klp_object *obj) obj->mod = NULL; klp_for_each_func(obj, func) - func->old_addr = 0; + func->old_func = NULL; } /* @@ -721,11 +721,11 @@ static int klp_init_object_loaded(struct klp_patch *patch, klp_for_each_func(obj, func) { ret = klp_find_object_symbol(obj->name, func->old_name, func->old_sympos, - &func->old_addr); + (unsigned long *)&func->old_func); if (ret) return ret; - ret = kallsyms_lookup_size_offset(func->old_addr, + ret = kallsyms_lookup_size_offset((unsigned long)func->old_func, &func->old_size, NULL); if (!ret) { pr_err("kallsyms size lookup failed for '%s'\n", diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index 7702cb4064fc..825022d70912 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -34,7 +34,7 @@ static LIST_HEAD(klp_ops); -struct klp_ops *klp_find_ops(unsigned long old_addr) +struct klp_ops *klp_find_ops(void *old_func) { struct klp_ops *ops; struct klp_func *func; @@ -42,7 +42,7 @@ struct klp_ops *klp_find_ops(unsigned long old_addr) list_for_each_entry(ops, &klp_ops, node) { func = list_first_entry(&ops->func_stack, struct klp_func, stack_node); - if (func->old_addr == old_addr) + if (func->old_func == old_func) return ops; } @@ -142,17 +142,18 @@ static void klp_unpatch_func(struct klp_func *func) if (WARN_ON(!func->patched)) return; - if (WARN_ON(!func->old_addr)) + if (WARN_ON(!func->old_func)) return; - ops = klp_find_ops(func->old_addr); + ops = klp_find_ops(func->old_func); if (WARN_ON(!ops)) return; if (list_is_singular(&ops->func_stack)) { unsigned long ftrace_loc; - ftrace_loc = klp_get_ftrace_location(func->old_addr); + ftrace_loc = + klp_get_ftrace_location((unsigned long)func->old_func); if (WARN_ON(!ftrace_loc)) return; @@ -174,17 +175,18 @@ static int klp_patch_func(struct klp_func *func) struct klp_ops *ops; int ret; - if (WARN_ON(!func->old_addr)) + if (WARN_ON(!func->old_func)) return -EINVAL; if (WARN_ON(func->patched)) return -EINVAL; - ops = klp_find_ops(func->old_addr); + ops = klp_find_ops(func->old_func); if (!ops) { unsigned long ftrace_loc; - ftrace_loc = klp_get_ftrace_location(func->old_addr); + ftrace_loc = + klp_get_ftrace_location((unsigned long)func->old_func); if (!ftrace_loc) { pr_err("failed to find location for function '%s'\n", func->old_name); diff --git a/kernel/livepatch/patch.h b/kernel/livepatch/patch.h index e72d8250d04b..a9b16e513656 100644 --- a/kernel/livepatch/patch.h +++ b/kernel/livepatch/patch.h @@ -10,7 +10,7 @@ * struct klp_ops - structure for tracking registered ftrace ops structs * * A single ftrace_ops is shared between all enabled replacement functions - * (klp_func structs) which have the same old_addr. This allows the switch + * (klp_func structs) which have the same old_func. This allows the switch * between function versions to happen instantaneously by updating the klp_ops * struct's func_stack list. The winner is the klp_func at the top of the * func_stack (front of the list). @@ -25,7 +25,7 @@ struct klp_ops { struct ftrace_ops fops; }; -struct klp_ops *klp_find_ops(unsigned long old_addr); +struct klp_ops *klp_find_ops(void *old_func); int klp_patch_object(struct klp_object *obj); void klp_unpatch_object(struct klp_object *obj); diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index 304d5eb8a98c..f27a378ad5e1 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -224,11 +224,11 @@ static int klp_check_stack_func(struct klp_func *func, * Check for the to-be-patched function * (the previous func). */ - ops = klp_find_ops(func->old_addr); + ops = klp_find_ops(func->old_func); if (list_is_singular(&ops->func_stack)) { /* original function */ - func_addr = func->old_addr; + func_addr = (unsigned long)func->old_func; func_size = func->old_size; } else { /* previously patched function */ -- 2.13.7