From d926ee92e84146ff85877b15d9ac0c7cd7c422c6 Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Mon, 29 Apr 2024 16:27:55 -0400 Subject: tpm: TPM2B formatted buffers 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: James Bottomley Reviewed-by: Stefan Berger Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm-buf.c | 38 +++++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index 2f2710ca6f6d..d679dc1cecc7 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); @@ -73,8 +103,6 @@ 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; @@ -87,7 +115,11 @@ 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); -- cgit v1.2.3