Messages in this thread | | | Subject | Re: [PATCH v2 1/2] tpm: Fix error handling in async work | From | Jarkko Sakkinen <> | Date | Wed, 05 Jan 2022 22:05:18 +0200 |
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On Tue, 2021-12-28 at 21:06 -0800, Tadeusz Struk wrote: > When an invalid (non existing) handle is used in a tpm command, ~~~ TPM
> that uses the resource manager interface (/dev/tpmrm0) the resource > manager tries to load it from its internal cache, but fails and > returns an -EINVAL error to the caller. The async handler doesn't > handle these error cases currently and the condition in the poll > handler never returns mask with EPOLLIN set. > The result is that the poll call blocks and the application gets > stuck > until the user_read_timer wakes it up after 120 sec. > Make sure that error conditions also contribute to the poll mask > so that a correct error code could passed back to the caller.
I'm not sure what "making sure" means.
> > Cc: Jarkko Sakkinen <jarkko@kernel.org> > Cc: Jason Gunthorpe <jgg@ziepe.ca> > Cc: <linux-integrity@vger.kernel.org> > Cc: <stable@vger.kernel.org> > Cc: <linux-kernel@vger.kernel.org> > Fixes: 9e1b74a63f77 ("tpm: add support for nonblocking operation") > Signed-off-by: Tadeusz Struk <tstruk@gmail.com> > --- > Changes in v2: > - Updated commit message with better problem description. > - Fixed typeos. > --- > drivers/char/tpm/tpm-dev-common.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/tpm-dev-common.c > b/drivers/char/tpm/tpm-dev-common.c > index c08cbb306636..fe2679f84cb6 100644 > --- a/drivers/char/tpm/tpm-dev-common.c > +++ b/drivers/char/tpm/tpm-dev-common.c > @@ -69,7 +69,7 @@ static void tpm_dev_async_work(struct work_struct > *work) > ret = tpm_dev_transmit(priv->chip, priv->space, priv- > >data_buffer, > sizeof(priv->data_buffer)); > tpm_put_ops(priv->chip); > - if (ret > 0) { > + if (ret != 0) {
What if ret < 0?
You should explain this change in the commit message. Also, consider adding an inline comment.
> priv->response_length = ret; > mod_timer(&priv->user_read_timer, jiffies + (120 * > HZ)); > }
BR, Jarkko
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