Re: [PATCH v3 01/16] tpm: use tpm_buf in tpm_transmit_cmd() as the IO parameter

Stefan Berger
2018-11-05T21:48:25Z

On 11/4/18 8:45 PM, Jarkko Sakkinen wrote:
> Since we pass an initialized struct tpm_buf instance in every call site
> now, it is cleaner to pass that directly to the tpm_transmit_cmd() as
> the TPM command/response buffer.
>
> Fine-tune a little bit tpm_transmit() and tpm_transmit_cmd() comments
> while doing this.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
> drivers/char/tpm/tpm-interface.c | 67 +++++++++++++++++--------------
> drivers/char/tpm/tpm-sysfs.c | 2 +-
> drivers/char/tpm/tpm.h | 5 +--
> drivers/char/tpm/tpm1-cmd.c | 26 ++++--------
> drivers/char/tpm/tpm2-cmd.c | 37 +++++++----------
> drivers/char/tpm/tpm2-space.c | 4 +-
> drivers/char/tpm/tpm_vtpm_proxy.c | 3 +-
> 7 files changed, 64 insertions(+), 80 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index d9439f9abe78..64510ed81b46 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -298,23 +298,22 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
>
> /**
> * tpm_transmit - Internal kernel interface to transmit TPM commands.
> + * @chip: a TPM chip to use
> + * @space: a TPM space
> + * @buf: a TPM command buffer
> + * @bufsiz: length of the TPM command buffer
> + * @flags: TPM transmit flags
> *
> - * @chip: TPM chip to use
> - * @space: tpm space
> - * @buf: TPM command buffer
> - * @bufsiz: length of the TPM command buffer
> - * @flags: tpm transmit flags - bitmap
> + * A wrapper around tpm_try_transmit() that handles TPM2_RC_RETRY returns from
> + * the TPM and retransmits the command after a delay up to a maximum wait of
> + * TPM2_DURATION_LONG.
> *
> - * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
> - * returns from the TPM and retransmits the command after a delay up
> - * to a maximum wait of TPM2_DURATION_LONG.
> - *
> - * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
> - * only
> + * Note that TPM 1.x never returns TPM2_RC_RETRY so the retry logic is TPM 2.0
> + * only.
> *
> * Return:
> - * the length of the return when the operation is successful.
> - * A negative number for system errors (errno).
> + * * The response length - OK
> + * * -errno - A system error
> */
> ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> u8 *buf, size_t bufsiz, unsigned int flags)
> @@ -365,33 +364,31 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> }
> return ret;
> }
> +
> /**
> * tpm_transmit_cmd - send a tpm command to the device
> - * The function extracts tpm out header return code
> - *
> - * @chip: TPM chip to use
> - * @space: tpm space
> - * @buf: TPM command buffer
> - * @bufsiz: length of the buffer
> - * @min_rsp_body_length: minimum expected length of response body
> - * @flags: tpm transmit flags - bitmap
> - * @desc: command description used in the error message
> + * @chip: a TPM chip to use
> + * @space: a TPM space
> + * @buf: a TPM command buffer
> + * @min_rsp_body_length: minimum expected length of response body
> + * @flags: TPM transmit flags
> + * @desc: command description used in the error message
> *
> * Return:
> - * 0 when the operation is successful.
> - * A negative number for system errors (errno).
> - * A positive number for a TPM error.
> + * * 0 - OK
> + * * -errno - A system error
> + * * TPM_RC - A TPM error
> */
> ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
> - void *buf, size_t bufsiz,
> - size_t min_rsp_body_length, unsigned int flags,
> - const char *desc)
> + struct tpm_buf *buf, size_t min_rsp_body_length,
> + unsigned int flags, const char *desc)
> {
> - const struct tpm_output_header *header = buf;
> + const struct tpm_output_header *header =
> + (struct tpm_output_header *)buf->data;
> int err;
> ssize_t len;
>
> - len = tpm_transmit(chip, space, buf, bufsiz, flags);
> + len = tpm_transmit(chip, space, buf->data, PAGE_SIZE, flags);
> if (len < 0)
> return len;
>
> @@ -528,14 +525,22 @@ EXPORT_SYMBOL_GPL(tpm_pcr_extend);
> */
> int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
> {
> + struct tpm_buf buf;
> int rc;
>
> chip = tpm_find_get_ops(chip);
> if (!chip)
> return -ENODEV;
>
> - rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
> + rc = tpm_buf_init(&buf, 0, 0);
> + if (rc)
> + goto out;
> +
> + memcpy(buf.data, cmd, buflen);

Nit: buflen -> cmd_len

> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
> "attempting to a send a command");
> + tpm_buf_destroy(&buf);
> +out:
> tpm_put_ops(chip);
> return rc;
> }
> diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
> index b88e08ec2c59..c2769e55cb6c 100644
> --- a/drivers/char/tpm/tpm-sysfs.c
> +++ b/drivers/char/tpm/tpm-sysfs.c
> @@ -53,7 +53,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
>
> tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay));
>
> - rc = tpm_transmit_cmd(chip, NULL, tpm_buf.data, PAGE_SIZE,
> + rc = tpm_transmit_cmd(chip, NULL, &tpm_buf,
> READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
> "attempting to read the PUBEK");
> if (rc) {
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index f27d1f38a93d..49bca4d1e786 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -503,9 +503,8 @@ enum tpm_transmit_flags {
> ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> u8 *buf, size_t bufsiz, unsigned int flags);
> ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
> - void *buf, size_t bufsiz,
> - size_t min_rsp_body_length, unsigned int flags,
> - const char *desc);
> + struct tpm_buf *buf, size_t min_rsp_body_length,
> + unsigned int flags, const char *desc);
> int tpm_get_timeouts(struct tpm_chip *);
> int tpm_auto_startup(struct tpm_chip *chip);
>
> diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
> index 6f306338953b..f19b7c1ff800 100644
> --- a/drivers/char/tpm/tpm1-cmd.c
> +++ b/drivers/char/tpm/tpm1-cmd.c
> @@ -334,11 +334,9 @@ static int tpm1_startup(struct tpm_chip *chip)
>
> tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
> "attempting to start the TPM");
> -
> tpm_buf_destroy(&buf);
> -
> return rc;
> }
>
> @@ -462,9 +460,7 @@ int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash,
> tpm_buf_append_u32(&buf, pcr_idx);
> tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
> - TPM_DIGEST_SIZE, 0, log_msg);
> -
> + rc = tpm_transmit_cmd(chip, NULL, &buf, TPM_DIGEST_SIZE, 0, log_msg);
> tpm_buf_destroy(&buf);
> return rc;
> }
> @@ -494,11 +490,9 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
> tpm_buf_append_u32(&buf, 4);
> tpm_buf_append_u32(&buf, subcap_id);
> }
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
> - min_cap_length, 0, desc);
> + rc = tpm_transmit_cmd(chip, NULL, &buf, min_cap_length, 0, desc);
> if (!rc)
> *cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
> -
> tpm_buf_destroy(&buf);
> return rc;
> }
> @@ -537,7 +531,7 @@ int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
> do {
> tpm_buf_append_u32(&buf, num_bytes);
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
> + rc = tpm_transmit_cmd(chip, NULL, &buf,
> sizeof(out->rng_data_len), 0,
> "attempting get random");
> if (rc)
> @@ -583,8 +577,7 @@ int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
>
> tpm_buf_append_u32(&buf, pcr_idx);
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
> - TPM_DIGEST_SIZE, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &buf, TPM_DIGEST_SIZE, 0,
> "attempting to read a pcr value");
> if (rc)
> goto out;
> @@ -618,11 +611,8 @@ static int tpm1_continue_selftest(struct tpm_chip *chip)
> if (rc)
> return rc;
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
> - 0, 0, "continue selftest");
> -
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, "continue selftest");
> tpm_buf_destroy(&buf);
> -
> return rc;
> }
>
> @@ -747,9 +737,7 @@ int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
> return rc;
> /* now do the actual savestate */
> for (try = 0; try < TPM_RETRY; try++) {
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
> - 0, 0, NULL);
> -
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, NULL);
> /*
> * If the TPM indicates that it is too busy to respond to
> * this command then retry before giving up. It can take
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index a6bec13afa69..2bcf470c8e5d 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -197,8 +197,8 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
> tpm_buf_append(&buf, (const unsigned char *)pcr_select,
> sizeof(pcr_select));
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
> - res_buf ? "attempting to read a pcr value" : NULL);
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, res_buf ?
> + "attempting to read a pcr value" : NULL);
> if (rc == 0 && res_buf) {
> out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
> memcpy(res_buf, out->digest, SHA1_DIGEST_SIZE);
> @@ -264,7 +264,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
> }
> }
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
> "attempting extend a PCR value");
>
> tpm_buf_destroy(&buf);
> @@ -309,7 +309,7 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
> do {
> tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
> tpm_buf_append_u16(&buf, num_bytes);
> - err = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
> + err = tpm_transmit_cmd(chip, NULL, &buf,
> offsetof(struct tpm2_get_random_out,
> buffer),
> 0, "attempting get random");
> @@ -362,9 +362,7 @@ void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
>
> tpm_buf_append_u32(&buf, handle);
>
> - (void) tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, flags,
> - "flushing context");
> -
> + tpm_transmit_cmd(chip, NULL, &buf, 0, flags, "flushing context");
> tpm_buf_destroy(&buf);
> }
>
> @@ -478,8 +476,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> goto out;
> }
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 4, 0,
> - "sealing data");
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 4, 0, "sealing data");
> if (rc)
> goto out;
>
> @@ -561,8 +558,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
> goto out;
> }
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 4, flags,
> - "loading blob");
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 4, flags, "loading blob");
> if (!rc)
> *blob_handle = be32_to_cpup(
> (__be32 *) &buf.data[TPM_HEADER_SIZE]);
> @@ -612,8 +608,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
> options->blobauth /* hmac */,
> TPM_DIGEST_SIZE);
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 6, flags,
> - "unsealing");
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 6, flags, "unsealing");
> if (rc > 0)
> rc = -EPERM;
>
> @@ -703,7 +698,7 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
> tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
> tpm_buf_append_u32(&buf, property_id);
> tpm_buf_append_u32(&buf, 1);
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, NULL);
> if (!rc) {
> out = (struct tpm2_get_cap_out *)
> &buf.data[TPM_HEADER_SIZE];
> @@ -733,8 +728,7 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
> if (rc)
> return;
> tpm_buf_append_u16(&buf, shutdown_type);
> - tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
> - "stopping the TPM");
> + tpm_transmit_cmd(chip, NULL, &buf, 0, 0, "stopping the TPM");
> tpm_buf_destroy(&buf);
> }
>
> @@ -763,7 +757,7 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
> return rc;
>
> tpm_buf_append_u8(&buf, full);
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
> "attempting the self test");
> tpm_buf_destroy(&buf);
>
> @@ -800,7 +794,7 @@ int tpm2_probe(struct tpm_chip *chip)
> tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
> tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
> tpm_buf_append_u32(&buf, 1);
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0, NULL);
> /* We ignore TPM return codes on purpose. */
> if (rc >= 0) {
> out = (struct tpm_output_header *)buf.data;
> @@ -839,7 +833,7 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
> tpm_buf_append_u32(&buf, 0);
> tpm_buf_append_u32(&buf, 1);
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 9, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 9, 0,
> "get tpm pcr allocation");
> if (rc)
> goto out;
> @@ -911,8 +905,7 @@ static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
> tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
> tpm_buf_append_u32(&buf, nr_commands);
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
> - 9 + 4 * nr_commands, 0, NULL);
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 9 + 4 * nr_commands, 0, NULL);
> if (rc) {
> tpm_buf_destroy(&buf);
> goto out;
> @@ -969,7 +962,7 @@ static int tpm2_startup(struct tpm_chip *chip)
> return rc;
>
> tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
> "attempting to start the TPM");
> tpm_buf_destroy(&buf);
>
> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
> index dcdfde3c253e..1131a8e7b79b 100644
> --- a/drivers/char/tpm/tpm2-space.c
> +++ b/drivers/char/tpm/tpm2-space.c
> @@ -83,7 +83,7 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
> body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
> tpm_buf_append(&tbuf, &buf[*offset], body_size);
>
> - rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 4,
> + rc = tpm_transmit_cmd(chip, NULL, &tbuf, 4,
> TPM_TRANSMIT_NESTED, NULL);
> if (rc < 0) {
> dev_warn(&chip->dev, "%s: failed with a system error %d\n",
> @@ -132,7 +132,7 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
>
> tpm_buf_append_u32(&tbuf, handle);
>
> - rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 0,
> + rc = tpm_transmit_cmd(chip, NULL, &tbuf, 0,
> TPM_TRANSMIT_NESTED, NULL);
> if (rc < 0) {
> dev_warn(&chip->dev, "%s: failed with a system error %d\n",
> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
> index 87a0ce47f201..5f95fbfb7f6b 100644
> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> @@ -417,8 +417,7 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality)
>
> proxy_dev->state |= STATE_DRIVER_COMMAND;
>
> - rc = tpm_transmit_cmd(chip, NULL, buf.data, tpm_buf_length(&buf), 0,
> - TPM_TRANSMIT_NESTED,
> + rc = tpm_transmit_cmd(chip, NULL, &buf, 0, TPM_TRANSMIT_NESTED,
> "attempting to set locality");
>
> proxy_dev->state &= ~STATE_DRIVER_COMMAND;

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>