On Mon, Aug 29, 2016 at 06:25:21PM +0300, Jarkko Sakkinen wrote:

On Sun, Aug 28, 2016 at 12:51:49PM -0600, Jason Gunthorpe wrote:

quoted

On Sun, Aug 28, 2016 at 08:36:52AM +0200, Jarkko Sakkinen wrote:

quoted

@@ -576,7 +576,8 @@ static int tpm2_load(struct tpm_chip *chip,
 		goto out;
 	}
 
-	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob");
+	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, TPM_TRANSMIT_UNLOCKED,
+			      "loading blob");

I still don't like this, required mutex's should not be split outside the
function that needs them without more a more obvious indication:

quoted

+	mutex_lock(&chip->tpm_mutex);
 	rc = tpm2_load(chip, payload, options, &blob_handle);
 	if (rc)
-		return rc;

I recommend you stick with the idiom and do this:

        mutex_lock(&chip->tpm_mutex);
  	rc = tpm2_load(chip, payload, options, &blob_handle, TPM_TRANSMIT_UNLOCKED);

Which makes it easy to see we are doing it right everywhere.

Why consume stack for unnecessary stuff? This is a static function. For
me this sounds like cutting hairs really.

Well, tpm2_load looks like any other normal command that would grab
the mutex, so something has to be done to indicate to the reader it is
the unlocked version.

I wouldn't worry about the stack, the compiler will inline that away
anyhow.

One thing that would improve readability would be to rename internal
functions tpm2_load and tpm2_unseal to tpm2_load_cmd and tpm2_unseal_cmd
in order to underline that they are command wrappers and not to mix with
tpm2_unseal_trusted().

That seems reasonable as well, as long as all _cmd varients are unlocked.

Jason