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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7E551C71157 for ; Wed, 18 Jun 2025 14:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9tObTLoBeN2CnE4Xxv7FNpSNs5jg5Z1CGWaVpXt6sHw=; b=Cb448MKp7Y4bmShMrEkhfalfdk /n/AbVWtOl7uVAV7Vb/KuY6mPjqBfYTxkdEBOVUr50Ca+TLvmoXW6LlgVnM+I1eH1dZuwz5TUTkov bDy1PyicyJClwYTl6GGWEA7NRhXYYQoQJlgFMy1PhCNdopQKCqmB7T95v3E0n4RbrlJd1eEew42TI ZFQdn4YMkoU/eh1JDUhnCc0oTuhDox/pe5k3vw3p1nJ6FIMKpQR1hKCNNC2uSAPMjygaVfUVXPWi4 1eLcEdSRTlRLY9WZQvqBB23OPHX1acSNhZQNBx5MMzNykEcT/k5N1xhiqgdomthu8Pzf1nh6wKILl AxupQhYw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uRtpJ-0000000AREF-1pkm; Wed, 18 Jun 2025 14:31:45 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uRpwj-00000009lgM-3IQi for linux-arm-kernel@lists.infradead.org; Wed, 18 Jun 2025 10:23:10 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E16731D13; Wed, 18 Jun 2025 03:22:48 -0700 (PDT) Received: from e129823.cambridge.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 24DD93F66E; Wed, 18 Jun 2025 03:23:08 -0700 (PDT) From: Yeoreum Yun To: jarkko@kernel.org, sudeep.holla@arm.com, peterhuewe@gmx.de, jgg@ziepe.ca, stuart.yoder@arm.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, Yeoreum Yun Subject: [PATCH v4 2/2] tpm: tpm_crb_ffa: try to probe tpm_crb_ffa when it's built-in Date: Wed, 18 Jun 2025 11:23:02 +0100 Message-Id: <20250618102302.2379029-3-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250618102302.2379029-1-yeoreum.yun@arm.com> References: <20250618102302.2379029-1-yeoreum.yun@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250618_032309_866852_D520F0B7 X-CRM114-Status: GOOD ( 19.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org To generate the boot_aggregate log in the IMA subsystem using TPM PCR values, the TPM driver must be built as built-in and must be probed before the IMA subsystem is initialized. However, when the TPM device operates over the FF-A protocol using the CRB interface, probing fails and returns -EPROBE_DEFER if the tpm_crb_ffa device — an FF-A device that provides the communication interface to the tpm_crb driver — has not yet been probed. This issue occurs because both crb_acpi_driver_init() and tpm_crb_ffa_driver_init() are registered with device_initcall. As a result, crb_acpi_driver_init() may be invoked before tpm_crb_ffa_driver_init(), which is responsible for probing the tpm_crb_ffa device. When this happens, IMA fails to detect the TPM device and logs the following message: | ima: No TPM chip found, activating TPM-bypass! Consequently, it cannot generate the boot_aggregate log with the PCR values provided by the TPM. To resolve this issue, the tpm_crb_ffa_init() function explicitly attempts to probe the tpm_crb_ffa by register tpm_crb_ffa driver so that when tpm_crb_ffa device is created before tpm_crb_ffa_init(), probe the tpm_crb_ffa device in tpm_crb_ffa_init() to finish probe the TPM device completely. This ensures that the TPM device using CRB over FF-A can be successfully probed, even if crb_acpi_driver_init() is called first. Signed-off-by: Yeoreum Yun --- drivers/char/tpm/tpm_crb_ffa.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/tpm_crb_ffa.c b/drivers/char/tpm/tpm_crb_ffa.c index 4ead61f01299..462fcf610020 100644 --- a/drivers/char/tpm/tpm_crb_ffa.c +++ b/drivers/char/tpm/tpm_crb_ffa.c @@ -115,6 +115,7 @@ struct tpm_crb_ffa { }; static struct tpm_crb_ffa *tpm_crb_ffa; +static struct ffa_driver tpm_crb_ffa_driver; static int tpm_crb_ffa_to_linux_errno(int errno) { @@ -168,13 +169,23 @@ static int tpm_crb_ffa_to_linux_errno(int errno) */ int tpm_crb_ffa_init(void) { + int ret = 0; + + if (!IS_MODULE(CONFIG_TCG_ARM_CRB_FFA)) { + ret = ffa_register(&tpm_crb_ffa_driver); + if (ret) { + tpm_crb_ffa = ERR_PTR(-ENODEV); + return ret; + } + } + if (!tpm_crb_ffa) - return -ENOENT; + ret = -ENOENT; if (IS_ERR_VALUE(tpm_crb_ffa)) - return -ENODEV; + ret = -ENODEV; - return 0; + return ret; } EXPORT_SYMBOL_GPL(tpm_crb_ffa_init); @@ -369,7 +380,9 @@ static struct ffa_driver tpm_crb_ffa_driver = { .id_table = tpm_crb_ffa_device_id, }; +#ifdef MODULE module_ffa_driver(tpm_crb_ffa_driver); +#endif MODULE_AUTHOR("Arm"); MODULE_DESCRIPTION("TPM CRB FFA driver"); -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}