| Message ID | 20180228195819.22231-4-jarkko.sakkinen@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
. . . 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
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
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 5f92141b1e16..36f6b0ac412b 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -856,19 +856,22 @@ static int tpm2_do_selftest(struct tpm_chip *chip) */ int tpm2_probe(struct tpm_chip *chip) { - struct tpm2_cmd cmd; + struct tpm_output_header *out; + struct tpm_buf buf; int rc; - cmd.header.in = tpm2_get_tpm_pt_header; - cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES); - cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100); - cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1); - - rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, 0, NULL); + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); + if (rc) + return rc; + tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES); + tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS); + tpm_buf_append_u32(&buf, 1); + rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL); + tpm_buf_destroy(&buf); if (rc < 0) return rc; - - if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS) + out = (struct tpm_output_header *)buf.data; + if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS) chip->flags |= TPM_CHIP_FLAG_TPM2; return 0;
In order to make struct tpm_buf the first class object for constructing TPM commands, migrate tpm2_probe() to use it. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> --- drivers/char/tpm/tpm2-cmd.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)