[SeaBIOS] [PATCH v2 1/3] tcgbios: pass returnCode through many functions

Kevin O'Connor kevin at koconnor.net
Tue Jan 16 19:16:38 CET 2018


On Tue, Jan 16, 2018 at 11:41:01AM -0500, Stefan Berger wrote:
> Pass the returnCode parameter through many of the functions so
> that we can get the TPM return code from hwtpm_transmit, if needed.
> 
> Signed-off-by: Stefan Berger <stefanb at linux.vnet.ibm.com>
> ---
>  src/hw/tpm_drivers.c |   8 ++-
>  src/hw/tpm_drivers.h |   2 +-
>  src/tcgbios.c        | 147 +++++++++++++++++++++++++++------------------------
>  3 files changed, 86 insertions(+), 71 deletions(-)
> 
> diff --git a/src/hw/tpm_drivers.c b/src/hw/tpm_drivers.c
> index a137e62..25f4f36 100644
> --- a/src/hw/tpm_drivers.c
> +++ b/src/hw/tpm_drivers.c
> @@ -377,7 +377,7 @@ tpmhw_is_present(void)
>  int
>  tpmhw_transmit(u8 locty, struct tpm_req_header *req,
>                 void *respbuffer, u32 *respbufferlen,
> -               enum tpmDurationType to_t)
> +               enum tpmDurationType to_t, u32 *returnCode)
>  {
>      if (TPMHW_driver_to_use == TPM_INVALID_DRIVER)
>          return -1;
> @@ -408,6 +408,12 @@ tpmhw_transmit(u8 locty, struct tpm_req_header *req,
>  
>      td->ready();
>  
> +    if (returnCode && *respbufferlen >= sizeof(struct tpm_rsp_header)) {
> +        struct tpm_rsp_header *r = respbuffer;
> +
> +        *returnCode = be32_to_cpu(r->errcode);
> +    }
> +
>      return 0;
>  }
[...]
> diff --git a/src/tcgbios.c b/src/tcgbios.c
> index 40b3028..730b5e7 100644
> --- a/src/tcgbios.c
> +++ b/src/tcgbios.c
> @@ -350,7 +350,8 @@ tpm_build_digest(struct tpm_log_entry *le, const u8 *sha1, int bigEndian)
>  // optional parameter (0, 1, or 2 bytes) and have no special response.
>  static int
>  tpm_simple_cmd(u8 locty, u32 ordinal
> -               , int param_size, u16 param, enum tpmDurationType to_t)
> +               , int param_size, u16 param, enum tpmDurationType to_t
> +               , u32 *returnCode)
>  {
>      struct {
>          struct tpm_req_header trqh;
> @@ -374,7 +375,8 @@ tpm_simple_cmd(u8 locty, u32 ordinal
>      u32 obuffer_len = sizeof(obuffer);
>      memset(obuffer, 0x0, sizeof(obuffer));
>  
> -    int ret = tpmhw_transmit(locty, &req.trqh, obuffer, &obuffer_len, to_t);
> +    int ret = tpmhw_transmit(locty, &req.trqh, obuffer, &obuffer_len, to_t,
> +                             returnCode);
>      ret = ret ? -1 : be32_to_cpu(trsh->errcode);

I'm not sure why this patch is necessary.  The callers of
tpmhw_transmit() can already extract the errcode.  Indeed,
tpm_simple_cmd() does just that and returns it to its callers via its
return code (see the last line of code above).

-Kevin



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