Re: [Qemu-devel] [PATCH V21 6/7] Add support for cancelling of a TPM command

[Corey Bryant]

On 02/11/2013 04:38 PM, Stefan Berger wrote:
> On 02/11/2013 01:46 PM, Corey Bryant wrote:
>
> > > @@ -79,25 +88,36 @@ static uint32_t
> > > tpm_passthrough_get_size_from_buffer(const uint8_t *buf)
> > >       return be32_to_cpu(resp->len);
> > >   }
> > >
> > > -static int tpm_passthrough_unix_tx_bufs(int tpm_fd,
> > > +static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
> > >                                           const uint8_t *in, uint32_t
> > > in_len,
> > >                                           uint8_t *out, uint32_t
> > > out_len)
> > >   {
> > >       int ret;
> > >
> > > -    ret = tpm_passthrough_unix_write(tpm_fd, in, in_len);
> > > +    tpm_pt->tpm_op_canceled = false;
> > > +    tpm_pt->tpm_executing = true;
> > > +
> > > +    ret = tpm_passthrough_unix_write(tpm_pt->tpm_fd, in, in_len);
> > >       if (ret != in_len) {
> > > -        error_report("tpm_passthrough: error while transmitting data "
> > > -                     "to TPM: %s (%i)\n",
> > > -                     strerror(errno), errno);
> > > +        if (!tpm_pt->tpm_op_canceled ||
> > > +            (tpm_pt->tpm_op_canceled && errno != ECANCELED)) {
> > > +            error_report("tpm_passthrough: error while transmitting
> > > data "
> > > +                         "to TPM: %s (%i)\n",
> > > +                         strerror(errno), errno);
> > > +        }
> > >           goto err_exit;
> > >       }
> > >
> > > -    ret = tpm_passthrough_unix_read(tpm_fd, out, out_len);
> > > +    tpm_pt->tpm_executing = false;
> > > +
> > > +    ret = tpm_passthrough_unix_read(tpm_pt->tpm_fd, out, out_len);
> > >       if (ret < 0) {
> > > -        error_report("tpm_passthrough: error while reading data from "
> > > -                     "TPM: %s (%i)\n",
> > > -                     strerror(errno), errno);
> > > +        if (!tpm_pt->tpm_op_canceled ||
> > > +            (tpm_pt->tpm_op_canceled && errno != ECANCELED)) {
> > > +            error_report("tpm_passthrough: error while reading data
> > > from "
> > > +                         "TPM: %s (%i)\n",
> > > +                         strerror(errno), errno);
> > > +        }
> > >       } else if (ret < sizeof(struct tpm_resp_hdr) ||
> > >                  tpm_passthrough_get_size_from_buffer(out) != ret) {
> > >           ret = -1;
> > > @@ -110,13 +130,15 @@ err_exit:
> > >           tpm_write_fatal_error_response(out, out_len);
> > >       }
> > >
> > > +    tpm_pt->tpm_executing = false;
> >
> > This can be removed because it is already false.
> Above I am setting tpm_executing to true before the write to the device.
> If an error occurred, we goto to the exit with the above statement. I am
> also setting tpm_executing to false before the reading of the result. So
> in case of an error this statement is need.

You're right.  My mistake, I missed the exit label.

--
Regards,
Corey Bryant