On Tue, Dec 09, 2025 at 09:39:02AM +0200, Jarkko Sakkinen wrote: > 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 <[email protected]> > --- > drivers/char/tpm/tpm-buf.c | 25 ----------------------- > drivers/char/tpm/tpm2-cmd.c | 4 ++-- > drivers/char/tpm/tpm2-sessions.c | 4 ++-- > include/linux/tpm.h | 1 - > security/keys/trusted-keys/trusted_tpm2.c | 2 +- > 5 files changed, 5 insertions(+), 31 deletions(-) > > diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c > index 73be8a87b472..752c69b8a4f5 100644 > --- a/drivers/char/tpm/tpm-buf.c > +++ b/drivers/char/tpm/tpm-buf.c > @@ -40,7 +40,6 @@ static void __tpm_buf_reset(struct tpm_buf *buf, u16 > buf_size, u16 tag, u32 ordi > buf->flags = 0; > buf->length = sizeof(*head); > buf->capacity = buf_size - sizeof(*buf); > - buf->handles = 0; > head->tag = cpu_to_be16(tag); > head->length = cpu_to_be32(sizeof(*head)); > head->ordinal = cpu_to_be32(ordinal); > @@ -56,7 +55,6 @@ static void __tpm_buf_reset_sized(struct tpm_buf *buf, u16 > buf_size) > buf->flags = TPM_BUF_TPM2B; > buf->length = 2; > buf->capacity = buf_size - sizeof(*buf); > - buf->handles = 0; > buf->data[0] = 0; > buf->data[1] = 0; > } > @@ -177,29 +175,6 @@ 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 > - * @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_buf *buf, u32 handle) > -{ > - if (buf->flags & TPM_BUF_INVALID) > - return; > - > - if (buf->flags & TPM_BUF_TPM2B) { > - WARN(1, "tpm-buf: invalid type: TPM2B\n"); > - buf->flags |= TPM_BUF_INVALID; > - return; > - } > - > - tpm_buf_append_u32(buf, handle); > - buf->handles++; > -} > - > /** > * tpm_buf_read() - Read from a TPM buffer > * @buf: &tpm_buf instance > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > index 5b04e74b6377..d14e249831c7 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -205,7 +205,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, > return rc; > tpm_buf_append_hmac_session(chip, buf, 0, NULL, 0); > } else { > - tpm_buf_append_handle(buf, pcr_idx); > + tpm_buf_append_u32(buf, pcr_idx); > tpm_buf_append_auth(chip, buf, NULL, 0); > } > > @@ -281,7 +281,7 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, > size_t max) > TPM2_SA_CONTINUE_SESSION, > NULL, 0); > } else { > - offset = buf->handles * 4 + TPM_HEADER_SIZE; > + offset = TPM_HEADER_SIZE + sizeof(u32); > head = (struct tpm_header *)buf->data; > if (tpm_buf_length(buf) == offset) > head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); > diff --git a/drivers/char/tpm/tpm2-sessions.c > b/drivers/char/tpm/tpm2-sessions.c > index 62a200ae72d7..dfd1abe673bc 100644 > --- a/drivers/char/tpm/tpm2-sessions.c > +++ b/drivers/char/tpm/tpm2-sessions.c > @@ -261,7 +261,7 @@ int tpm_buf_append_name(struct tpm_chip *chip, struct > tpm_buf *buf, > } > > if (!tpm2_chip_auth(chip)) { > - tpm_buf_append_handle(buf, handle); > + tpm_buf_append_u32(buf, handle); > return 0; > } > > @@ -289,7 +289,7 @@ 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; > + int offset = TPM_HEADER_SIZE + sizeof(u32); > u32 len = 9 + passphrase_len; > > if (tpm_buf_length(buf) != offset) { > diff --git a/include/linux/tpm.h b/include/linux/tpm.h > index db716841973f..e20647cc0a0f 100644 > --- a/include/linux/tpm.h > +++ b/include/linux/tpm.h > @@ -437,7 +437,6 @@ 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_buf *buf, u32 handle); > > /* > * Check if TPM device is in the firmware upgrade mode. > diff --git a/security/keys/trusted-keys/trusted_tpm2.c > b/security/keys/trusted-keys/trusted_tpm2.c > index 7756aa839d81..0a07a18da2ed 100644 > --- a/security/keys/trusted-keys/trusted_tpm2.c > +++ b/security/keys/trusted-keys/trusted_tpm2.c > @@ -495,7 +495,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, > if (tpm2_chip_auth(chip)) { > tpm_buf_append_hmac_session(chip, buf, TPM2_SA_ENCRYPT, > NULL, 0); > } else { > - offset = buf->handles * 4 + TPM_HEADER_SIZE; > + offset = TPM_HEADER_SIZE + sizeof(u32);
Maybe it would be sensible to define: /* * Offset of the authorization area of a TPM command with a single * handle. */ #define TPM2_AUTH_OFFSET (TPM_HEADER_SIZE + sizeof(u32)) This would overall clarify how this code works. > head = (struct tpm_header *)buf->data; > if (tpm_buf_length(buf) == offset) > head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); > -- > 2.52.0 > BR, Jarkko
