Re: [PATCH v11 00/16] Remove nested TPM operations

On 2/7/19 8:51 PM, Stefan Berger wrote:

On 2/7/19 7:33 PM, Jarkko Sakkinen wrote:

quoted

On Thu, Feb 07, 2019 at 06:29:43PM -0500, Stefan Berger wrote:

quoted

On 2/7/19 4:29 PM, Jarkko Sakkinen wrote:

quoted

quoted

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index e74c5b7b64bf..52afe20cc8a1 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c

@@ -799,7 +799,9 @@ int tpm2_probe(struct tpm_chip *chip)

      tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
      tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
      tpm_buf_append_u32(&buf, 1);
+    tpm_chip_start(chip);
      rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
+    tpm_chip_stop(chip);

Thanks Stefan! I added call to tpm_tis_core as tpm2-cmd.c is to be kept
out of chip management common case being that you call 
tpm_try_get_ops(),
do 1-N TPM commands and release with tpm_put_ops(). These functions take
care starting and stopping the chip.

I fixed the 2nd issue in the master.

You also need to export the tpm_chip_start/stop symbols.


Master now seems to (still) have a problem when rmmod'ing:

A TPM error (325) occurred stopping the TPM. This happens at the same 
patch where I had to add the tpm_chip_start/stop above.

Here's my current overall patch against your master. I suppose the other 
tpm2_shutdown() for power management doesn't need the chip start ?

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 9865776ee2cd..f7147706a9c3 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c

@@ -115,6 +115,7 @@ int tpm_chip_start(struct tpm_chip *chip)

      return 0;
  }
+EXPORT_SYMBOL_GPL(tpm_chip_start);

  /**
   * tpm_chip_stop() - power off the TPM

@@ -131,7 +132,7 @@ void tpm_chip_stop(struct tpm_chip *chip)
      if (chip->ops->clk_enable)
          chip->ops->clk_enable(chip, false);
  }
-
+EXPORT_SYMBOL_GPL(tpm_chip_stop);

  /**
   * tpm_try_get_ops() - Get a ref to the tpm_chip

@@ -474,8 +475,11 @@ static void tpm_del_char_device(struct tpm_chip *chip)

      /* Make the driver uncallable. */
      down_write(&chip->ops_sem);
-    if (chip->flags & TPM_CHIP_FLAG_TPM2)
+    if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+        tpm_chip_start(chip, 0);
          tpm2_shutdown(chip, TPM2_SU_CLEAR);
+        tpm_chip_stop(chip, 0);
+    }
      chip->ops = NULL;
      up_write(&chip->ops_sem);
  }

diff --git a/drivers/char/tpm/tpm-interface.c 

b/drivers/char/tpm/tpm-interface.c
index 02e8cffd1163..fcd845ad8c3c 100644

--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c

@@ -124,6 +124,8 @@ static ssize_t tpm_try_transmit(struct tpm_chip 

*chip, void *buf, size_t bufsiz)
          dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %d\n", rc);
      } else if (len < TPM_HEADER_SIZE || len != 
be32_to_cpu(header->length))
          rc = -EFAULT;
+    else
+        rc = 0;

      return rc ? rc : len;
  }

quoted

  /Jarkko