RE: [PATCH v5 09/17] tpm: move tpm_validate_commmand() to tpm2-space.c

["Winkler, Tomas" <tomas.winkler@intel.com>]

> 
> Move tpm_validate_command() to tpm2-space.c and make it part of the
> tpm2_prepare_space() flow. Make cc resolution as part of the TPM space
> functionality in order to detach it from rest of the tpm_transmit() flow.
> 
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
> ---
>  drivers/char/tpm/tpm-interface.c | 72 +++++++-------------------------
>  drivers/char/tpm/tpm.h           |  9 ++--
>  drivers/char/tpm/tpm2-space.c    | 54 +++++++++++++++++++++---
>  3 files changed, 68 insertions(+), 67 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-
> interface.c
> index f2280bf15339..a6ffd0960ae5 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -62,47 +62,6 @@ unsigned long tpm_calc_ordinal_duration(struct
> tpm_chip *chip, u32 ordinal)  }
> EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
> 
> -static int tpm_validate_command(struct tpm_chip *chip,
> -				 struct tpm_space *space,
> -				 const u8 *cmd,
> -				 size_t len)
> -{
> -	const struct tpm_header *header = (const void *)cmd;
> -	int i;
> -	u32 cc;
> -	u32 attrs;
> -	unsigned int nr_handles;
> -
> -	if (len < TPM_HEADER_SIZE)
> -		return -EINVAL;
> -
> -	if (!space)
> -		return 0;
> -
> -	if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
> -		cc = be32_to_cpu(header->ordinal);
> -
> -		i = tpm2_find_cc(chip, cc);
> -		if (i < 0) {
> -			dev_dbg(&chip->dev, "0x%04X is an invalid
> command\n",
> -				cc);
> -			return -EOPNOTSUPP;
> -		}
> -
> -		attrs = chip->cc_attrs_tbl[i];
> -		nr_handles =
> -			4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) &
> GENMASK(2, 0));
> -		if (len < TPM_HEADER_SIZE + 4 * nr_handles)
> -			goto err_len;
> -	}
> -
> -	return 0;
> -err_len:
> -	dev_dbg(&chip->dev,
> -		"%s: insufficient command length %zu", __func__, len);
> -	return -EINVAL;
> -}
> -
>  static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)  {
>  	int rc;
> @@ -172,20 +131,8 @@ static ssize_t tpm_try_transmit(struct tpm_chip
> *chip,
>  	u32 count, ordinal;
>  	unsigned long stop;
> 
> -	rc = tpm_validate_command(chip, space, buf, bufsiz);
> -	if (rc == -EINVAL)
> -		return rc;
> -	/*
> -	 * If the command is not implemented by the TPM, synthesize a
> -	 * response with a TPM2_RC_COMMAND_CODE return for user-
> space.
> -	 */
> -	if (rc == -EOPNOTSUPP) {
> -		header->length = cpu_to_be32(sizeof(*header));
> -		header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
> -		header->return_code =
> cpu_to_be32(TPM2_RC_COMMAND_CODE |
> -
> TSS2_RESMGR_TPM_RC_LAYER);
> -		return sizeof(*header);
> -	}
> +	if (bufsiz < TPM_HEADER_SIZE)
> +		return -EINVAL;
> 
>  	if (bufsiz > TPM_BUFSIZE)
>  		bufsiz = TPM_BUFSIZE;
> @@ -200,7 +147,18 @@ static ssize_t tpm_try_transmit(struct tpm_chip
> *chip,
>  		return -E2BIG;
>  	}
> 
> -	rc = tpm2_prepare_space(chip, space, ordinal, buf);
> +	rc = tpm2_prepare_space(chip, space, buf, bufsiz);
> +	/*
> +	 * If the command is not implemented by the TPM, synthesize a
> +	 * response with a TPM2_RC_COMMAND_CODE return for user-
> space.
> +	 */
> +	if (rc == -EOPNOTSUPP) {
> +		header->length = cpu_to_be32(sizeof(*header));
> +		header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
> +		header->return_code =
> cpu_to_be32(TPM2_RC_COMMAND_CODE |
> +
> TSS2_RESMGR_TPM_RC_LAYER);
> +		return sizeof(*header);
> +	}
>  	if (rc)
>  		return rc;
> 
> @@ -249,7 +207,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip
> *chip,
>  	if (rc)
>  		tpm2_flush_space(chip);
>  	else
> -		rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
> +		rc = tpm2_commit_space(chip, space, buf, &len);
> 
>  	return rc ? rc : len;
>  }
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index
> 92638ec6ec97..68d78ebba032 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -264,6 +264,7 @@ struct tpm_chip {
>  #endif /* CONFIG_ACPI */
> 
>  	struct tpm_space work_space;
> +	u32 last_cc;
>  	u32 nr_commands;
>  	u32 *cc_attrs_tbl;
> 
> @@ -577,10 +578,10 @@ int tpm2_find_cc(struct tpm_chip *chip, u32 cc);
> int tpm2_init_space(struct tpm_space *space);  void tpm2_del_space(struct
> tpm_chip *chip, struct tpm_space *space);  void tpm2_flush_space(struct
> tpm_chip *chip); -int tpm2_prepare_space(struct tpm_chip *chip, struct
> tpm_space *space, u32 cc,
> -		       u8 *cmd);
> -int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
> -		      u32 cc, u8 *buf, size_t *bufsiz);
> +int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space,
> u8 *cmd,
> +		       size_t cmdsiz);
> +int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
> u8 *buf,
> +		       size_t *bufsiz);
> 
>  int tpm_bios_log_setup(struct tpm_chip *chip);  void
> tpm_bios_log_teardown(struct tpm_chip *chip); diff --git
> a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index
> 393d9aadadce..f35ac941c3a4 100644
> --- a/drivers/char/tpm/tpm2-space.c
> +++ b/drivers/char/tpm/tpm2-space.c
> @@ -264,14 +264,55 @@ static int tpm2_map_command(struct tpm_chip
> *chip, u32 cc, u8 *cmd)
>  	return 0;
>  }
> 
> -int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space,
> u32 cc,
> -		       u8 *cmd)
> +static int tpm_validate_command(struct tpm_chip *chip, struct tpm_space
> *space,
> +				const u8 *cmd, size_t len)
> +{
> +	const struct tpm_input_header *header = (const void *)cmd;
> +	int i;
> +	u32 cc;
> +	u32 attrs;
> +	unsigned int nr_handles;
> +
> +	if (len < TPM_HEADER_SIZE)
> +		return -EINVAL;
> +
> +	if (chip->nr_commands) {
> +		cc = be32_to_cpu(header->ordinal);
You initialized cc under if only 
> +
> +		i = tpm2_find_cc(chip, cc);
> +		if (i < 0) {
> +			dev_dbg(&chip->dev, "0x%04X is an invalid
> command\n",
> +				cc);
> +			return -EOPNOTSUPP;
> +		}
> +
> +		attrs = chip->cc_attrs_tbl[i];
> +		nr_handles =
> +			4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) &
> GENMASK(2, 0));
> +		if (len < TPM_HEADER_SIZE + 4 * nr_handles)
> +			goto err_len;
> +	}
> +
> +	return cc;
You can return uninitialized cc here.

> +err_len:
> +	dev_dbg(&chip->dev, "%s: insufficient command length %zu",
> __func__,
> +		len);
> +	return -EINVAL;
> +}
> +
> +int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space,
> u8 *cmd,
> +		       size_t cmdsiz)
>  {
>  	int rc;
> +	int cc;
> 
>  	if (!space)
>  		return 0;
> 
> +	cc = tpm_validate_command(chip, space, cmd, cmdsiz);
> +	if (cc < 0)
> +		return cc;
> +
>  	memcpy(&chip->work_space.context_tbl, &space->context_tbl,
>  	       sizeof(space->context_tbl));
>  	memcpy(&chip->work_space.session_tbl, &space->session_tbl, @@ -
> 291,6 +332,7 @@ int tpm2_prepare_space(struct tpm_chip *chip, struct
> tpm_space *space, u32 cc,
>  		return rc;
>  	}
> 
> +	chip->last_cc = cc;
>  	return 0;
>  }
> 
> @@ -489,8 +531,8 @@ static int tpm2_save_space(struct tpm_chip *chip)
>  	return 0;
>  }
> 
> -int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
> -		      u32 cc, u8 *buf, size_t *bufsiz)
> +int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
> u8 *buf,
> +		      size_t *bufsiz)
>  {
>  	struct tpm_header *header = (void *)buf;
>  	int rc;
> @@ -498,13 +540,13 @@ int tpm2_commit_space(struct tpm_chip *chip,
> struct tpm_space *space,
>  	if (!space)
>  		return 0;
> 
> -	rc = tpm2_map_response_header(chip, cc, buf, *bufsiz);
> +	rc = tpm2_map_response_header(chip, chip->last_cc, buf, *bufsiz);
>  	if (rc) {
>  		tpm2_flush_space(chip);
>  		goto out;
>  	}
> 
> -	rc = tpm2_map_response_body(chip, cc, buf, *bufsiz);
> +	rc = tpm2_map_response_body(chip, chip->last_cc, buf, *bufsiz);
>  	if (rc) {
>  		tpm2_flush_space(chip);
>  		goto out;
> --
> 2.19.1