[PATCH v9 09/11] tpm-buf: Remove tpm_buf_append_handle

Jarkko Sakkinen
2026-01-25T19:26:21Z

Since the number of handles is fixed to a single handle, eliminate all uses
of buf->handles and deduce values during compile-time.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
v2:
- Streamline the code change and remove dead code.
---
drivers/char/tpm/tpm-buf.c | 23 -----------------------
drivers/char/tpm/tpm2-cmd.c | 2 +-
drivers/char/tpm/tpm2-sessions.c | 14 ++------------
include/linux/tpm.h | 2 --
4 files changed, 3 insertions(+), 38 deletions(-)

diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
index dc882fc9fa9e..1d2b87455d3a 100644
--- a/drivers/char/tpm/tpm-buf.c
+++ b/drivers/char/tpm/tpm-buf.c
@@ -44,7 +44,6 @@ void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
head->tag = cpu_to_be16(tag);
head->length = cpu_to_be32(sizeof(*head));
head->ordinal = cpu_to_be32(ordinal);
- buf->handles = 0;
}
EXPORT_SYMBOL_GPL(tpm_buf_reset);

@@ -146,26 +145,6 @@ void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value)
}
EXPORT_SYMBOL_GPL(tpm_buf_append_u32);

-/**
- * tpm_buf_append_handle() - Add a handle
- * @chip: &tpm_chip instance
- * @buf: &tpm_buf instance
- * @handle: a TPM object handle
- *
- * Add a handle to the buffer, and increase the count tracking the number of
- * handles in the command buffer. Works only for command buffers.
- */
-void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle)
-{
- if (buf->flags & TPM_BUF_TPM2B) {
- dev_err(&chip->dev, "Invalid buffer type (TPM2B)\n");
- return;
- }
-
- tpm_buf_append_u32(buf, handle);
- buf->handles++;
-}
-
/**
* tpm_buf_read() - Read from a TPM buffer
* @buf: &tpm_buf instance
@@ -242,5 +221,3 @@ u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset)
return be32_to_cpu(value);
}
EXPORT_SYMBOL_GPL(tpm_buf_read_u32);
-
-
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 96a45391036c..39ef6b7a0fbc 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -210,7 +210,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
}
tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0);
} else {
- tpm_buf_append_handle(chip, &buf, pcr_idx);
+ tpm_buf_append_u32(&buf, pcr_idx);
tpm_buf_append_auth(chip, &buf, NULL, 0);
}

diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c
index 98cea20040cf..016bed63a755 100644
--- a/drivers/char/tpm/tpm2-sessions.c
+++ b/drivers/char/tpm/tpm2-sessions.c
@@ -268,7 +268,7 @@ int tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf,
}

if (!tpm2_chip_auth(chip)) {
- tpm_buf_append_handle(chip, buf, handle);
+ tpm_buf_append_u32(buf, handle);
return 0;
}

@@ -295,17 +295,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_append_name);
void tpm_buf_append_auth(struct tpm_chip *chip, struct tpm_buf *buf,
u8 *passphrase, int passphrase_len)
{
- /* offset tells us where the sessions area begins */
- int offset = buf->handles * 4 + TPM_HEADER_SIZE;
- u32 len = 9 + passphrase_len;
-
- if (tpm_buf_length(buf) != offset) {
- /* not the first session so update the existing length */
- len += get_unaligned_be32(&buf->data[offset]);
- put_unaligned_be32(len, &buf->data[offset]);
- } else {
- tpm_buf_append_u32(buf, len);
- }
+ tpm_buf_append_u32(buf, 9 + passphrase_len);
/* auth handle */
tpm_buf_append_u32(buf, TPM2_RS_PW);
/* nonce */
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 7468709ad245..e8339f0c9a2e 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -397,7 +397,6 @@ struct tpm_buf {
u32 flags;
u32 length;
u8 *data;
- u8 handles;
};

enum tpm2_object_attributes {
@@ -441,7 +440,6 @@ void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value);
u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset);
u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset);
u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset);
-void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle);

/*
* Check if TPM device is in the firmware upgrade mode.
--
2.52.0