lkml.org 
[lkml]   [2018]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/5] tpm: migrate tpm2_probe() to use struct tpm_buf
On Thu, Mar 01, 2018 at 02:10:17PM -0800, J Freyensee wrote:
> .
> .
> .
> I'm new to this area of the kernel, but I'm not getting these lines:
>
> > + rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
> > + tpm_buf_destroy(&buf);
> > if (rc < 0)
> Why is this if() check not directly after the tpm_transmit_cmd() call that
> sets rc?  Is it correct you want to destroy buf regardless of the
> tpm_transmit_cmd() outcome?
> > return rc;
> > -
> > - if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
> > + out = (struct tpm_output_header *)buf.data;
>
> So buf has been destroyed, buf.data sill has something valid to assign to
> out?
> > + if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
> > chip->flags |= TPM_CHIP_FLAG_TPM2;
> > return 0;
> Thanks,
> Jay

Nope it is a regression in the patch. Thank you :-) tpm_buf_destroy()
can be called if the response data is not needed other than everything
went OK (tpm_transmit_cmd() already digs this info).

/Jarkko

\
 
 \ /
  Last update: 2018-03-05 12:11    [W:0.061 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site