On Sat, Oct 08, 2016 at 10:15:56PM -0400, Nayna Jain wrote: > As per the TCG 2.0 spec, the extend operation should be done to > all active PCR banks. However, current TPM 2.0 support doesn't > have the capability implemented to get active PCR banks. > > This patch implements the TPM 2.0 capability TPM_CAP_PCRS to > retrieve active PCR banks from the TPM. > > Signed-off-by: Nayna Jain <na...@linux.vnet.ibm.com>
I'll try to give some guidelines how to get this done. > +#define TPM2_GET_CAPABILITY_IN_SIZE \ > + (sizeof(struct tpm_input_header) + \ > + sizeof(struct tpm2_get_cap_in)) > + > +static const struct tpm_input_header tpm2_get_capability_header = { > + .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS), > + .length = cpu_to_be32(TPM2_GET_CAPABILITY_IN_SIZE), > + .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY) > +}; > + > +int tpm2_get_capability(struct tpm_chip *chip, struct tpm2_get_cap_in > *cap_in, > + struct tpm2_get_cap_out *cap_out) > +{ > + > + struct tpm2_cmd cmd; > + int rc; > + u32 cap_id; > + > + cmd.header.in = tpm2_get_capability_header; > + cmd.params.get_cap_in.cap_id = cpu_to_be32(cap_in->cap_id); > + cmd.params.get_cap_in.property_id = cpu_to_be32(cap_in->property_id); > + cmd.params.get_cap_in.property_cnt = cpu_to_be32(cap_in->property_cnt); > + > + rc = tpm_transmit_cmd(chip, (const char *) &cmd, sizeof(cmd), 0, > + "attempting get capability operation"); > + if (rc < 0) > + return rc; > + cap_id = be32_to_cpu(cmd.params.get_cap_out.cap_data.cap_id); > + > + switch (cap_id) { > + case TPM2_CAP_PCRS: > + memcpy(&cap_out->cap_data, &cmd.params.get_cap_out.cap_data, > + sizeof(cmd.params.get_cap_out.cap_data)); > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return rc; I think it would be better to start with a function that grabs one attribute and call that in a loop. Performance is not an issue here and you are storing the result. Simpler is really better in this case. Rather refactor tpm2_get_tpm_pt to be more generic and call that in a loop. I don't think the performance is really an issue here and you anyway store the result to struct tpm_chip. Also, your implementation is not generic (more_data is not taken into account). I just sent patches that I've written for the access broker [1]. I think it'd be better if you would use them in your patch set. [1] https://lkml.org/lkml/2016/10/9/49 /Jarkko ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ tpmdd-devel mailing list tpmdd-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tpmdd-devel