From patchwork Tue Nov 21 22:31:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 13463714 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 9510F56752 for ; Tue, 21 Nov 2023 22:32:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Wbio7xVF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0DE4AC433C7; Tue, 21 Nov 2023 22:32:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700605924; bh=wugQtq5Ux8D+7D9eA8hGi3uOUUNxiJUru+mHy8L7ums=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wbio7xVFz03W1HAhQwS7i3kF9mIRjekZ11Go+lR0GQYDSguqosY7+aZk51+6IvBhZ rqF1i8GJ1Yae7hO1jZ+BPeQQ5clccl3gt03VIDt+ADy/eTYBkbupULdVWNeQAwK89D KtMKMB2HlmGHsKAo64hDTtB/D8a4Po4Is99R5+dDXxQMimXlgyzuochbX8ROOQEkx7 I+WkK9dEACri/Z3bwDJ33smCs3NMgvR6gXI7pSIGKEWTQoQviU2aU9TFPaMrfCw4qn s8rv5KOOBwUu91XKl1Y/VFZ0JpGdoM7D8h6wPSqEbjWbCb9nXrWTuaz7sca3e8hWnq GkgvZs8wfr+Ag== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , Peter Huewe , Jason Gunthorpe , Julien Gomes , James Bottomley , Jerry Snitselaar , Mario Limonciello Subject: [PATCH v5 6/8] tpm: TPM2B formatted buffers Date: Wed, 22 Nov 2023 00:31:18 +0200 Message-ID: <20231121223130.30824-7-jarkko@kernel.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231121223130.30824-1-jarkko@kernel.org> References: <20231121223130.30824-1-jarkko@kernel.org> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Declare tpm_buf_init_sized() and tpm_buf_reset_sized() for creating TPM2B formatted buffers. These buffers are also known as sized buffers in the specifications and literature. Signed-off-by: Jarkko Sakkinen --- v2: [2021-11-21] Refine the API according to the comments for https://lore.kernel.org/linux-integrity/20231024011531.442587-5-jarkko@kernel.org/ --- drivers/char/tpm/tpm-buf.c | 38 +++++++++++++++++++++++++++++++++++--- include/linux/tpm.h | 4 ++++ 2 files changed, 39 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index 3f39893f3bb1..099b4a56c5d5 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -47,6 +47,36 @@ void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) } EXPORT_SYMBOL_GPL(tpm_buf_reset); +/** + * tpm_buf_init_sized() - Allocate and initialize a sized (TPM2B) buffer + * @buf: A @tpm_buf + * + * Return: 0 or -ENOMEM + */ +int tpm_buf_init_sized(struct tpm_buf *buf) +{ + buf->data = (u8 *)__get_free_page(GFP_KERNEL); + if (!buf->data) + return -ENOMEM; + + tpm_buf_reset_sized(buf); + return 0; +} +EXPORT_SYMBOL_GPL(tpm_buf_init_sized); + +/** + * tpm_buf_reset_sized() - Initialize a sized buffer + * @buf: A &tpm_buf + */ +void tpm_buf_reset_sized(struct tpm_buf *buf) +{ + buf->flags = TPM_BUF_TPM2B; + buf->length = 2; + buf->data[0] = 0; + buf->data[1] = 0; +} +EXPORT_SYMBOL_GPL(tpm_buf_reset_sized); + void tpm_buf_destroy(struct tpm_buf *buf) { free_page((unsigned long)buf->data); @@ -72,8 +102,6 @@ EXPORT_SYMBOL_GPL(tpm_buf_length); */ void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length) { - struct tpm_header *head = (struct tpm_header *)buf->data; - /* Return silently if overflow has already happened. */ if (buf->flags & TPM_BUF_OVERFLOW) return; @@ -86,7 +114,11 @@ void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length) memcpy(&buf->data[buf->length], new_data, new_length); buf->length += new_length; - head->length = cpu_to_be32(buf->length); + + if (buf->flags & TPM_BUF_TPM2B) + ((__be16 *)buf->data)[0] = cpu_to_be16(buf->length - 2); + else + ((struct tpm_header *)buf->data)->length = cpu_to_be32(buf->length); } EXPORT_SYMBOL_GPL(tpm_buf_append); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 1d7b39b5c383..715db4a91c1f 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -300,6 +300,8 @@ struct tpm_header { enum tpm_buf_flags { /* the capacity exceeded: */ TPM_BUF_OVERFLOW = BIT(0), + /* TPM2B format: */ + TPM_BUF_TPM2B = BIT(1), }; /* @@ -328,6 +330,8 @@ struct tpm2_hash { int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal); void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal); +int tpm_buf_init_sized(struct tpm_buf *buf); +void tpm_buf_reset_sized(struct tpm_buf *buf); void tpm_buf_destroy(struct tpm_buf *buf); u32 tpm_buf_length(struct tpm_buf *buf); void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length);