Re: [PATCH v3 3/5] tpm: migrate tpm2_probe() to use struct tpm_buf

From: Mimi Zohar
Date: Mon Mar 05 2018 - 17:52:40 EST


Hi Jarrko,

On Mon, 2018-03-05 at 18:56 +0200, Jarkko Sakkinen wrote:
> 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@xxxxxxxxxxxxxxx>

With this patch, the Pi doesn't find the TPM. ÂI'm seeing the
following line in dmesg.

[ÂÂÂÂ1.087414] tpm_tis_spi: probe of spi0.0 failed with error 256

Mimi

> ---
> drivers/char/tpm/tpm2-cmd.c | 27 +++++++++++++++------------
> 1 file changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index abe6ef4a7a0b..890d83c5c78b 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -851,22 +851,25 @@ 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);
> - if (rc < 0)
> + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> + if (rc)
> return rc;
> -
> - if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
> + 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);
> + if (rc < 0)
> + goto out;
> + 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;
> +out:
> + tpm_buf_destroy(&buf);
> + return rc;
> }
> EXPORT_SYMBOL_GPL(tpm2_probe);
>