Re: [PATCH v3 08/16] tpm: move tpm_validate_commmand() to tpm2-space.c

Stefan Berger
2018-11-05T22:36:12Z

On 11/4/18 8:45 PM, Jarkko Sakkinen wrote:
> 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>
> ---
> 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 422e3bb0bd3d..3bf0c51b7b4f 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_input_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;
>
> @@ -251,7 +209,7 @@ 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 229ac42b644e..8503dd261897 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;
>
> @@ -580,10 +581,10 @@ 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 3d5f9577e5de..20c295fadd50 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)

Nit: len -> cmdsiz (like below)

> +{
> + 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);
> +
> + 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;
> +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_output_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;

Rest looks good.

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