From patchwork Wed Sep 23 16:13:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 254206 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=-14.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 BBCCFC4727F for ; Wed, 23 Sep 2020 16:15:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6354820936 for ; Wed, 23 Sep 2020 16:15:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600877700; bh=jBPk9GYHchZOkBmUWbnB7ym+PkKvrGJQed6G/FmGfrw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xgEgFKAaYA8XwEXFYwDn8JzRMi+tggIbA4u/kkebK2PVy1V9uv0lZWUypRQBr0CxP 12P9K45z3wqlYgMDoqGXGTsHZwdc1X3nNxjnc+RyvT1QGd/Z5ohM39VVowAK957N23 9F2B6hXYhKbKks+mF+R5xHslv/Hdtt2qm4lpApK8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726678AbgIWQO7 (ORCPT ); Wed, 23 Sep 2020 12:14:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:41858 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbgIWQO7 (ORCPT ); Wed, 23 Sep 2020 12:14:59 -0400 Received: from e123331-lin.nice.arm.com (lfbn-nic-1-188-42.w2-15.abo.wanadoo.fr [2.15.37.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5670821BE5; Wed, 23 Sep 2020 16:14:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600877698; bh=jBPk9GYHchZOkBmUWbnB7ym+PkKvrGJQed6G/FmGfrw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IuM1FobYpIunjTJWK7dJWn7EA8cdsFf5/ToAAbijFKdjNakRdxWeL4mTR+wXlsuUf fVGGrIhGWDrgqMTlDUiFU/iYve4rn5NadeaJs3lGkCrZHHLpMVBJeF3hkaW10Zohc7 v7dSEaFotzXO7PYfNbi5maeaCKYCqVZ7T7fZ3Bcs= From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: linux-efi@vger.kernel.org, Ard Biesheuvel , Matthew Garrett , Peter Jones , Kees Cook , Anton Vorontsov , Colin Cross , Tony Luck Subject: [PATCH 1/7] efi: pstore: disentangle from deprecated efivars module Date: Wed, 23 Sep 2020 18:13:58 +0200 Message-Id: <20200923161404.17811-2-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200923161404.17811-1-ardb@kernel.org> References: <20200923161404.17811-1-ardb@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org The EFI pstore implementation relies on the 'efivars' abstraction, which encapsulates the EFI variable store in a way that can be overridden by other backing stores, like the Google SMI one. On top of that, the EFI pstore implementation also relies on the efivars.ko module, which is a separate layer built on top of the 'efivars' abstraction that exposes the [deprecated] sysfs entries for each variable that exists in the backing store. Since the efivars.ko module is deprecated, and all users appear to have moved to the efivarfs file system instead, let's prepare for its removal, by removing EFI pstore's dependency on it. Signed-off-by: Ard Biesheuvel Acked-by: Kees Cook --- drivers/firmware/efi/Kconfig | 2 +- drivers/firmware/efi/efi-pstore.c | 76 ++++++++++++++++++-- drivers/firmware/efi/efivars.c | 41 +---------- include/linux/efi.h | 4 -- 4 files changed, 74 insertions(+), 49 deletions(-) diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 3939699e62fe..dd8d10817bdf 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -26,7 +26,7 @@ config EFI_ESRT config EFI_VARS_PSTORE tristate "Register efivars backend for pstore" - depends on EFI_VARS && PSTORE + depends on PSTORE default y help Say Y here to enable use efivars as a backend to pstore. This diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c index feb7fe6f2da7..785f5e6b3a41 100644 --- a/drivers/firmware/efi/efi-pstore.c +++ b/drivers/firmware/efi/efi-pstore.c @@ -8,6 +8,8 @@ #define DUMP_NAME_LEN 66 +#define EFIVARS_DATA_SIZE_MAX 1024 + static bool efivars_pstore_disable = IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE); @@ -18,6 +20,8 @@ module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); EFI_VARIABLE_BOOTSERVICE_ACCESS | \ EFI_VARIABLE_RUNTIME_ACCESS) +static LIST_HEAD(efi_pstore_list); + static int efi_pstore_open(struct pstore_info *psi) { psi->data = NULL; @@ -126,7 +130,7 @@ static inline int __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry, if (entry->deleting) { list_del(&entry->list); efivar_entry_iter_end(); - efivar_unregister(entry); + kfree(entry); if (efivar_entry_iter_begin()) return -EINTR; } else if (turn_off_scanning) @@ -169,7 +173,7 @@ static int efi_pstore_sysfs_entry_iter(struct pstore_record *record) { struct efivar_entry **pos = (struct efivar_entry **)&record->psi->data; struct efivar_entry *entry, *n; - struct list_head *head = &efivar_sysfs_list; + struct list_head *head = &efi_pstore_list; int size = 0; int ret; @@ -314,12 +318,12 @@ static int efi_pstore_erase_name(const char *name) if (efivar_entry_iter_begin()) return -EINTR; - found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, + found = __efivar_entry_iter(efi_pstore_erase_func, &efi_pstore_list, efi_name, &entry); efivar_entry_iter_end(); if (found && !entry->scanning) - efivar_unregister(entry); + kfree(entry); return found ? 0 : -ENOENT; } @@ -354,14 +358,76 @@ static struct pstore_info efi_pstore_info = { .erase = efi_pstore_erase, }; +static int efi_pstore_callback(efi_char16_t *name, efi_guid_t vendor, + unsigned long name_size, void *data) +{ + struct efivar_entry *entry; + int ret; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + memcpy(entry->var.VariableName, name, name_size); + entry->var.VendorGuid = vendor; + + ret = efivar_entry_add(entry, &efi_pstore_list); + if (ret) + kfree(entry); + + return ret; +} + +static int efi_pstore_update_entry(efi_char16_t *name, efi_guid_t vendor, + unsigned long name_size, void *data) +{ + struct efivar_entry *entry = data; + + if (efivar_entry_find(name, vendor, &efi_pstore_list, false)) + return 0; + + memcpy(entry->var.VariableName, name, name_size); + memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); + + return 1; +} + +static void efi_pstore_update_entries(struct work_struct *work) +{ + struct efivar_entry *entry; + int err; + + /* Add new sysfs entries */ + while (1) { + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return; + + err = efivar_init(efi_pstore_update_entry, entry, + false, &efi_pstore_list); + if (!err) + break; + + efivar_entry_add(entry, &efi_pstore_list); + } + + kfree(entry); +} + static __init int efivars_pstore_init(void) { + int ret; + if (!efivars_kobject() || !efivar_supports_writes()) return 0; if (efivars_pstore_disable) return 0; + ret = efivar_init(efi_pstore_callback, NULL, true, &efi_pstore_list); + if (ret) + return ret; + efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); if (!efi_pstore_info.buf) return -ENOMEM; @@ -374,6 +440,8 @@ static __init int efivars_pstore_init(void) efi_pstore_info.bufsize = 0; } + INIT_WORK(&efivar_work, efi_pstore_update_entries); + return 0; } diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c index dcea137142b3..f39321dbc29f 100644 --- a/drivers/firmware/efi/efivars.c +++ b/drivers/firmware/efi/efivars.c @@ -24,8 +24,7 @@ MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); MODULE_ALIAS("platform:efivars"); -LIST_HEAD(efivar_sysfs_list); -EXPORT_SYMBOL_GPL(efivar_sysfs_list); +static LIST_HEAD(efivar_sysfs_list); static struct kset *efivars_kset; @@ -591,42 +590,6 @@ create_efivars_bin_attributes(void) return error; } -static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor, - unsigned long name_size, void *data) -{ - struct efivar_entry *entry = data; - - if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false)) - return 0; - - memcpy(entry->var.VariableName, name, name_size); - memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); - - return 1; -} - -static void efivar_update_sysfs_entries(struct work_struct *work) -{ - struct efivar_entry *entry; - int err; - - /* Add new sysfs entries */ - while (1) { - entry = kzalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - return; - - err = efivar_init(efivar_update_sysfs_entry, entry, - false, &efivar_sysfs_list); - if (!err) - break; - - efivar_create_sysfs_entry(entry); - } - - kfree(entry); -} - static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor, unsigned long name_size, void *data) { @@ -701,8 +664,6 @@ int efivars_sysfs_init(void) return error; } - INIT_WORK(&efivar_work, efivar_update_sysfs_entries); - return 0; } EXPORT_SYMBOL_GPL(efivars_sysfs_init); diff --git a/include/linux/efi.h b/include/linux/efi.h index 73db1ae04cef..a470256f5ee3 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -984,8 +984,6 @@ struct efivar_entry { bool deleting; }; -extern struct list_head efivar_sysfs_list; - static inline void efivar_unregister(struct efivar_entry *var) { @@ -1043,8 +1041,6 @@ void efivar_run_worker(void); #if defined(CONFIG_EFI_VARS) || defined(CONFIG_EFI_VARS_MODULE) int efivars_sysfs_init(void); -#define EFIVARS_DATA_SIZE_MAX 1024 - #endif /* CONFIG_EFI_VARS */ extern bool efi_capsule_pending(int *reset_type);