From patchwork Thu Sep 28 20:24:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 13403500 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 472434CFA3 for ; Thu, 28 Sep 2023 20:24:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44CE0C433CC; Thu, 28 Sep 2023 20:24:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695932670; bh=YwkcC//jT+wVcODAvmEk31HCnO5Vo+gEW1wd+qFiIJc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t3bVyRelpGxRmOg6PaM5Fj0+lKdoXKhZi/NNwHCJu5ECTPA40eMquxiKW+SCpLzBO 9C2wMWUEi11GDqmattCqULfR1OV81IJFyW3QIJzxt5J3TM9cwVZCgaPZMr39VIPNmG FaVHQWTiX/dJCMCMhiYutETNEnMNfXM26FGcdCBSLRUIiRbiPjsZ7ZiB103hWH+AqY be8+osGtesWLclMTjRsiE0eTluYU/MEw5AevbxPzEw3420oZEieCf/RUK65OKcGRG3 BpBxsyYW0E14L3MLUGfbR1D3F8PopUsVsY2DLC2zlKXg07Hhwi2LrNQ3q6Z7XgRAx9 dqUal9Dajze2A== From: KP Singh To: linux-security-module@vger.kernel.org, bpf@vger.kernel.org Cc: paul@paul-moore.com, keescook@chromium.org, casey@schaufler-ca.com, song@kernel.org, daniel@iogearbox.net, ast@kernel.org, kpsingh@kernel.org, renauld@google.com, Kui-Feng Lee , Andrii Nakryiko Subject: [PATCH v5 2/5] security: Count the LSMs enabled at compile time Date: Thu, 28 Sep 2023 22:24:07 +0200 Message-ID: <20230928202410.3765062-3-kpsingh@kernel.org> X-Mailer: git-send-email 2.42.0.582.g8ccd20d70d-goog In-Reply-To: <20230928202410.3765062-1-kpsingh@kernel.org> References: <20230928202410.3765062-1-kpsingh@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 These macros are a clever trick to determine a count of the number of LSMs that are enabled in the config to ascertain the maximum number of static calls that need to be configured per LSM hook. Without this one would need to generate static calls for the total number of LSMs in the kernel (even if they are not compiled) times the number of LSM hooks which ends up being quite wasteful. Suggested-by: Kui-Feng Lee Suggested-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: KP Singh Reviewed-by: Kees Cook --- include/linux/lsm_count.h | 114 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 include/linux/lsm_count.h diff --git a/include/linux/lsm_count.h b/include/linux/lsm_count.h new file mode 100644 index 000000000000..dbb3c8573959 --- /dev/null +++ b/include/linux/lsm_count.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Copyright (C) 2023 Google LLC. + */ + +#ifndef __LINUX_LSM_COUNT_H +#define __LINUX_LSM_COUNT_H + +#include + +#ifdef CONFIG_SECURITY + +/* + * Macros to count the number of LSMs enabled in the kernel at compile time. + */ + +/* + * Capabilities is enabled when CONFIG_SECURITY is enabled. + */ +#if IS_ENABLED(CONFIG_SECURITY) +#define CAPABILITIES_ENABLED 1, +#else +#define CAPABILITIES_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_SELINUX) +#define SELINUX_ENABLED 1, +#else +#define SELINUX_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_SMACK) +#define SMACK_ENABLED 1, +#else +#define SMACK_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_APPARMOR) +#define APPARMOR_ENABLED 1, +#else +#define APPARMOR_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_TOMOYO) +#define TOMOYO_ENABLED 1, +#else +#define TOMOYO_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_YAMA) +#define YAMA_ENABLED 1, +#else +#define YAMA_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_LOADPIN) +#define LOADPIN_ENABLED 1, +#else +#define LOADPIN_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) +#define LOCKDOWN_ENABLED 1, +#else +#define LOCKDOWN_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_SAFESETID) +#define SAFESETID_ENABLED 1, +#else +#define SAFESETID_ENABLED +#endif + +#if IS_ENABLED(CONFIG_BPF_LSM) +#define BPF_LSM_ENABLED 1, +#else +#define BPF_LSM_ENABLED +#endif + +#if IS_ENABLED(CONFIG_SECURITY_LANDLOCK) +#define LANDLOCK_ENABLED 1, +#else +#define LANDLOCK_ENABLED +#endif + +/* + * There is a trailing comma that we need to be accounted for. This is done by + * using a skipped argument in __COUNT_LSMS + */ +#define __COUNT_LSMS(skipped_arg, args...) COUNT_ARGS(args...) +#define COUNT_LSMS(args...) __COUNT_LSMS(args) + +#define MAX_LSM_COUNT \ + COUNT_LSMS( \ + CAPABILITIES_ENABLED \ + SELINUX_ENABLED \ + SMACK_ENABLED \ + APPARMOR_ENABLED \ + TOMOYO_ENABLED \ + YAMA_ENABLED \ + LOADPIN_ENABLED \ + LOCKDOWN_ENABLED \ + SAFESETID_ENABLED \ + BPF_LSM_ENABLED \ + LANDLOCK_ENABLED) + +#else + +#define MAX_LSM_COUNT 0 + +#endif /* CONFIG_SECURITY */ + +#endif /* __LINUX_LSM_COUNT_H */