* [PATCH] tpm-dev: Require response to be read only if there actually is a response
@ 2018-12-06 17:58 Alexander Steffen
2018-12-12 17:53 ` Jarkko Sakkinen
0 siblings, 1 reply; 2+ messages in thread
From: Alexander Steffen @ 2018-12-06 17:58 UTC (permalink / raw)
To: Jarkko Sakkinen, Tadeusz Struk
Cc: jgg, linux-integrity, linux-security-module, linux-kernel,
Alexander Steffen
If the tpm_transmit call in tpm_common_write fails for any reason, there is
no response that could be read. Therefore, do not require the application
to issue a read call before sending further commands. This restores the
behavior from before support for partial reads was introduced.
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
---
Feel free to merge this into Tadeusz' original commit.
drivers/char/tpm/tpm-dev-common.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
index 344739223451..5eecad233ea1 100644
--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -140,7 +140,8 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf,
* tpm_read or a user_read_timer timeout. This also prevents split
* buffered writes from blocking here.
*/
- if (!priv->response_read || priv->command_enqueued) {
+ if ((!priv->response_read && priv->response_length) ||
+ priv->command_enqueued) {
ret = -EBUSY;
goto out;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] tpm-dev: Require response to be read only if there actually is a response
2018-12-06 17:58 [PATCH] tpm-dev: Require response to be read only if there actually is a response Alexander Steffen
@ 2018-12-12 17:53 ` Jarkko Sakkinen
0 siblings, 0 replies; 2+ messages in thread
From: Jarkko Sakkinen @ 2018-12-12 17:53 UTC (permalink / raw)
To: Alexander Steffen
Cc: Tadeusz Struk, jgg, linux-integrity, linux-security-module, linux-kernel
On Thu, Dec 06, 2018 at 06:58:01PM +0100, Alexander Steffen wrote:
> If the tpm_transmit call in tpm_common_write fails for any reason, there is
> no response that could be read. Therefore, do not require the application
> to issue a read call before sending further commands. This restores the
> behavior from before support for partial reads was introduced.
>
> Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
> ---
> Feel free to merge this into Tadeusz' original commit.
Thank you, good catch.
My PR is a bit late becuse just came from Oregon back to Finland so
I'll follow your advice and squash this. Thanks again.
/Jarkko
^ permalink raw reply [flat|nested] 2+ messages in thread
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