| Message ID | 20181206175801.23048-1-Alexander.Steffen@infineon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tpm-dev: Require response to be read only if there actually is a response | expand |
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
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; }
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(-)