Hello Jason, Thanks a lot for your feedback. On 11/17/2017 05:57 PM, Jason Gunthorpe wrote: > On Fri, Nov 17, 2017 at 11:07:24AM +0100, Javier Martinez Canillas wrote: > >> This patch is an RFC because I'm not sure if this is the correct way to fix this >> issue. I'm not that familiar with the TPM driver so may had missed some details. >> >> And example of user-space getting confused by the TPM chardev returning -EINVAL >> when sending a not supported TPM command can be seen in this tpm2-tools issue: >> >> https://github.com/intel/tpm2-tools/issues/621 > > I think this is a user space bug, unfortunately. > No worries, as mentioned I posted this RFC mostly to raise awareness of the issue and to get feedback on how it could be properly solved. > We talked about this when the spaces code was first written and it > seemed the best was to just return EINVAL to indicate that the kernel > could not accept the request. > > This result is semantically different from the TPM could not execute > or complete the request. > Yes, the problem with that is user-space not having enough information about what went wrong. Right now the TCTI layer just reports TSS2_BASE_RC_IO_ERROR in this case and can't be blamed. Maybe Philip can comment how this could be handled in user-space since he has a much better understanding of the TCTI and SAPI layers. > Regarding your specific issue, can you make the command you want to > use validate? Would that make sense? > Sorry, I'm not sure to understand what you meant. Could you please elaborate? Best regards, -- Javier Martinez Canillas Software Engineer - Desktop Hardware Enablement Red Hat
