From patchwork Tue Mar 22 14:03:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aaron Tomlin X-Patchwork-Id: 12788399 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5935AC433EF for ; Tue, 22 Mar 2022 14:04:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236054AbiCVOFg (ORCPT ); Tue, 22 Mar 2022 10:05:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236130AbiCVOFd (ORCPT ); Tue, 22 Mar 2022 10:05:33 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3C51B2F3AE for ; Tue, 22 Mar 2022 07:04:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647957840; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5Rx7F+K+0k86/LXscs1Sbp2hURc7HubcG1GfiaI2pKg=; b=HB+yNtLRDY07J3hgkyg+Z0CaTRYHHHFKrSOl8jQdlS63STI6jeM2TcrZ8xW5BV+PBk9MAC EtoZyhukiqP+Qa2DP41wLHfd5Rwrdck/0PXFCmV/KuxUEcvRfKiRFGvdxRflrJK3cmEdma ENqSRDNZqnQHp68PzATLR3NTtYveMf8= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-542-a1TElq6-M5Ss2U9hVu2rdQ-1; Tue, 22 Mar 2022 10:03:59 -0400 X-MC-Unique: a1TElq6-M5Ss2U9hVu2rdQ-1 Received: by mail-wm1-f71.google.com with SMTP id r9-20020a1c4409000000b0038c15a1ed8cso1345301wma.7 for ; Tue, 22 Mar 2022 07:03:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5Rx7F+K+0k86/LXscs1Sbp2hURc7HubcG1GfiaI2pKg=; b=dWc4QG0zUnXpuEGK5TLrFeE4oxNT4HuN00kquhlkU9n8zWFRSdDqsII/bsMBatLCOO M4sIetO7mpmDBZZY17D+25Ne9gX9eDfFjwBBv/N6WJ5uPPeM8+SFF4RPpjDhmrWPL0hS wrXLZjRojs+UR/L6QbbrEf52QV9WSSvsHYHJJft0TZ/UdKZcX8Jk9YFAbD9TfO782G8z Ydx7UysNckzRrl+lw2FF5pU3GOSXqp9kl53Jzoqe2Qb89BGJ/A+WeSKG1gWRy8tD4FcT aef2iwzpESi7bZxe2/LsEmOKEakLRudMQdRo8o9m/CdPATlIG/0BjIf2yxzlonpTGRK4 qzRQ== X-Gm-Message-State: AOAM530e/Xmfg6fB6HUODpEEPzXRPz97HJfdyD61NzSQJ0i2XbnrA/xJ t3kJDpL5TCJ5KU5pg0CQiNPCBCzKJDxw4trBYTcejyK/myrnaPeLdgKaMzOQU0nnfPOiGoILsi1 aPyI/2BCDJpmytPTYtF7KVQZb X-Received: by 2002:a05:6000:15ce:b0:204:1113:b053 with SMTP id y14-20020a05600015ce00b002041113b053mr8391614wry.701.1647957837798; Tue, 22 Mar 2022 07:03:57 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyZAJm+eqFCjPL2124VDQpWK/bx1xe1SyxrAIwwscaJF8ySaouY027WcATdiGidP6e9d2rDuQ== X-Received: by 2002:a05:6000:15ce:b0:204:1113:b053 with SMTP id y14-20020a05600015ce00b002041113b053mr8391584wry.701.1647957837500; Tue, 22 Mar 2022 07:03:57 -0700 (PDT) Received: from localhost (cpc111743-lutn13-2-0-cust979.9-3.cable.virginm.net. [82.17.115.212]) by smtp.gmail.com with ESMTPSA id g10-20020adfe40a000000b00203eb3551f0sm18115487wrm.117.2022.03.22.07.03.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Mar 2022 07:03:56 -0700 (PDT) From: Aaron Tomlin To: mcgrof@kernel.org, christophe.leroy@csgroup.eu Cc: cl@linux.com, mbenes@suse.cz, akpm@linux-foundation.org, jeyu@kernel.org, linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org, void@manifault.com, atomlin@atomlin.com, allen.lkml@gmail.com, joe@perches.com, msuchanek@suse.de, oleksandr@natalenko.name, jason.wessel@windriver.com, pmladek@suse.com, daniel.thompson@linaro.org, hch@infradead.org Subject: [PATCH v12 04/14] module: Move livepatch support to a separate file Date: Tue, 22 Mar 2022 14:03:34 +0000 Message-Id: <20220322140344.556474-5-atomlin@redhat.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220322140344.556474-1-atomlin@redhat.com> References: <20220322140344.556474-1-atomlin@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: No functional change. This patch migrates livepatch support (i.e. used during module add/or load and remove/or deletion) from core module code into kernel/module/livepatch.c. At the moment it contains code to persist Elf information about a given livepatch module, only. The new file was added to MAINTAINERS. Reviewed-by: Petr Mladek Tested-by: Petr Mladek Signed-off-by: Aaron Tomlin --- MAINTAINERS | 1 + include/linux/module.h | 9 ++-- kernel/module/Makefile | 1 + kernel/module/internal.h | 22 ++++++++ kernel/module/livepatch.c | 74 +++++++++++++++++++++++++++ kernel/module/main.c | 102 ++++---------------------------------- 6 files changed, 111 insertions(+), 98 deletions(-) create mode 100644 kernel/module/livepatch.c diff --git a/MAINTAINERS b/MAINTAINERS index 012c9f55a06d..20205d2ef87c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11179,6 +11179,7 @@ F: arch/s390/include/asm/livepatch.h F: arch/x86/include/asm/livepatch.h F: include/linux/livepatch.h F: kernel/livepatch/ +F: kernel/module/livepatch.c F: lib/livepatch/ F: samples/livepatch/ F: tools/testing/selftests/livepatch/ diff --git a/include/linux/module.h b/include/linux/module.h index 1e135fd5c076..7ec9715de7dc 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -663,17 +663,14 @@ static inline bool module_requested_async_probing(struct module *module) return module && module->async_probe_requested; } -#ifdef CONFIG_LIVEPATCH static inline bool is_livepatch_module(struct module *mod) { +#ifdef CONFIG_LIVEPATCH return mod->klp; -} -#else /* !CONFIG_LIVEPATCH */ -static inline bool is_livepatch_module(struct module *mod) -{ +#else return false; +#endif } -#endif /* CONFIG_LIVEPATCH */ bool is_module_sig_enforced(void); void set_module_sig_enforced(void); diff --git a/kernel/module/Makefile b/kernel/module/Makefile index cdd5c61b8c7f..ed3aacb04f17 100644 --- a/kernel/module/Makefile +++ b/kernel/module/Makefile @@ -10,3 +10,4 @@ KCOV_INSTRUMENT_module.o := n obj-y += main.o obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o obj-$(CONFIG_MODULE_SIG) += signing.o +obj-$(CONFIG_LIVEPATCH) += livepatch.o diff --git a/kernel/module/internal.h b/kernel/module/internal.h index e0775e66bcf7..ad7a444253ed 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -57,6 +57,28 @@ struct load_info { int mod_verify_sig(const void *mod, struct load_info *info); +#ifdef CONFIG_LIVEPATCH +int copy_module_elf(struct module *mod, struct load_info *info); +void free_module_elf(struct module *mod); +#else /* !CONFIG_LIVEPATCH */ +static inline int copy_module_elf(struct module *mod, struct load_info *info) +{ + return 0; +} + +static inline void free_module_elf(struct module *mod) { } +#endif /* CONFIG_LIVEPATCH */ + +static inline bool set_livepatch_module(struct module *mod) +{ +#ifdef CONFIG_LIVEPATCH + mod->klp = true; + return true; +#else + return false; +#endif +} + #ifdef CONFIG_MODULE_DECOMPRESS int module_decompress(struct load_info *info, const void *buf, size_t size); void module_decompress_cleanup(struct load_info *info); diff --git a/kernel/module/livepatch.c b/kernel/module/livepatch.c new file mode 100644 index 000000000000..486d4ff92719 --- /dev/null +++ b/kernel/module/livepatch.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Module livepatch support + * + * Copyright (C) 2016 Jessica Yu + */ + +#include +#include +#include +#include "internal.h" + +/* + * Persist Elf information about a module. Copy the Elf header, + * section header table, section string table, and symtab section + * index from info to mod->klp_info. + */ +int copy_module_elf(struct module *mod, struct load_info *info) +{ + unsigned int size, symndx; + int ret; + + size = sizeof(*mod->klp_info); + mod->klp_info = kmalloc(size, GFP_KERNEL); + if (!mod->klp_info) + return -ENOMEM; + + /* Elf header */ + size = sizeof(mod->klp_info->hdr); + memcpy(&mod->klp_info->hdr, info->hdr, size); + + /* Elf section header table */ + size = sizeof(*info->sechdrs) * info->hdr->e_shnum; + mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); + if (!mod->klp_info->sechdrs) { + ret = -ENOMEM; + goto free_info; + } + + /* Elf section name string table */ + size = info->sechdrs[info->hdr->e_shstrndx].sh_size; + mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); + if (!mod->klp_info->secstrings) { + ret = -ENOMEM; + goto free_sechdrs; + } + + /* Elf symbol section index */ + symndx = info->index.sym; + mod->klp_info->symndx = symndx; + + /* + * For livepatch modules, core_kallsyms.symtab is a complete + * copy of the original symbol table. Adjust sh_addr to point + * to core_kallsyms.symtab since the copy of the symtab in module + * init memory is freed at the end of do_init_module(). + */ + mod->klp_info->sechdrs[symndx].sh_addr = (unsigned long)mod->core_kallsyms.symtab; + + return 0; + +free_sechdrs: + kfree(mod->klp_info->sechdrs); +free_info: + kfree(mod->klp_info); + return ret; +} + +void free_module_elf(struct module *mod) +{ + kfree(mod->klp_info->sechdrs); + kfree(mod->klp_info->secstrings); + kfree(mod->klp_info); +} diff --git a/kernel/module/main.c b/kernel/module/main.c index 5f5e21f972dd..3596ebf3a6c3 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2043,81 +2043,6 @@ static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, } #endif /* CONFIG_STRICT_MODULE_RWX */ -#ifdef CONFIG_LIVEPATCH -/* - * Persist Elf information about a module. Copy the Elf header, - * section header table, section string table, and symtab section - * index from info to mod->klp_info. - */ -static int copy_module_elf(struct module *mod, struct load_info *info) -{ - unsigned int size, symndx; - int ret; - - size = sizeof(*mod->klp_info); - mod->klp_info = kmalloc(size, GFP_KERNEL); - if (mod->klp_info == NULL) - return -ENOMEM; - - /* Elf header */ - size = sizeof(mod->klp_info->hdr); - memcpy(&mod->klp_info->hdr, info->hdr, size); - - /* Elf section header table */ - size = sizeof(*info->sechdrs) * info->hdr->e_shnum; - mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); - if (mod->klp_info->sechdrs == NULL) { - ret = -ENOMEM; - goto free_info; - } - - /* Elf section name string table */ - size = info->sechdrs[info->hdr->e_shstrndx].sh_size; - mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); - if (mod->klp_info->secstrings == NULL) { - ret = -ENOMEM; - goto free_sechdrs; - } - - /* Elf symbol section index */ - symndx = info->index.sym; - mod->klp_info->symndx = symndx; - - /* - * For livepatch modules, core_kallsyms.symtab is a complete - * copy of the original symbol table. Adjust sh_addr to point - * to core_kallsyms.symtab since the copy of the symtab in module - * init memory is freed at the end of do_init_module(). - */ - mod->klp_info->sechdrs[symndx].sh_addr = \ - (unsigned long) mod->core_kallsyms.symtab; - - return 0; - -free_sechdrs: - kfree(mod->klp_info->sechdrs); -free_info: - kfree(mod->klp_info); - return ret; -} - -static void free_module_elf(struct module *mod) -{ - kfree(mod->klp_info->sechdrs); - kfree(mod->klp_info->secstrings); - kfree(mod->klp_info); -} -#else /* !CONFIG_LIVEPATCH */ -static int copy_module_elf(struct module *mod, struct load_info *info) -{ - return 0; -} - -static void free_module_elf(struct module *mod) -{ -} -#endif /* CONFIG_LIVEPATCH */ - void __weak module_memfree(void *module_region) { /* @@ -3092,30 +3017,23 @@ static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned l return 0; } -#ifdef CONFIG_LIVEPATCH static int check_modinfo_livepatch(struct module *mod, struct load_info *info) { - if (get_modinfo(info, "livepatch")) { - mod->klp = true; + if (!get_modinfo(info, "livepatch")) + /* Nothing more to do */ + return 0; + + if (set_livepatch_module(mod)) { add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n", - mod->name); - } - - return 0; -} -#else /* !CONFIG_LIVEPATCH */ -static int check_modinfo_livepatch(struct module *mod, struct load_info *info) -{ - if (get_modinfo(info, "livepatch")) { - pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", - mod->name); - return -ENOEXEC; + mod->name); + return 0; } - return 0; + pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", + mod->name); + return -ENOEXEC; } -#endif /* CONFIG_LIVEPATCH */ static void check_modinfo_retpoline(struct module *mod, struct load_info *info) {