From: Stefan Berger <[email protected]>
When rngd is run as root then lots of these types of message will appear
in the kernel log if the TPM has been configure to provide random bytes:
[ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4
The issue is caused by the following call that is interrupted while
waiting for the TPM's response.
sig = wait_event_interruptible(ibmvtpm->wq,
!ibmvtpm->tpm_processing_cmd);
The solution is to use wait_event() instead.
To recreat the issue start rngd like this:
sudo rngd -r /dev/hwrng -t
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1981473
Fixes: 6674ff145eef ("tpm_ibmvtpm: properly handle interrupted packet receptions")
Cc: Nayna Jain <[email protected]>
Cc: George Wilson <[email protected]>
Reported-by: Nageswara R Sastry <[email protected]>
Signed-off-by: Stefan Berger <[email protected]>
---
drivers/char/tpm/tpm_ibmvtpm.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 903604769de9..99b0442a5fdf 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -106,16 +106,13 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
u16 len;
- int sig;
if (!ibmvtpm->rtce_buf) {
dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
return 0;
}
- sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
- if (sig)
- return -EINTR;
+ wait_event(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
len = ibmvtpm->res_len;
@@ -206,7 +203,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
bool retry = true;
- int rc, sig;
+ int rc;
if (!ibmvtpm->rtce_buf) {
dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
@@ -224,9 +221,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
dev_info(ibmvtpm->dev,
"Need to wait for TPM to finish\n");
/* wait for previous command to finish */
- sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
- if (sig)
- return -EINTR;
+ wait_event(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
}
spin_lock(&ibmvtpm->rtce_lock);
@@ -551,7 +546,7 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
/* len of the data in rtce buffer */
ibmvtpm->res_len = be16_to_cpu(crq->len);
ibmvtpm->tpm_processing_cmd = false;
- wake_up_interruptible(&ibmvtpm->wq);
+ wake_up(&ibmvtpm->wq);
return;
default:
return;
--
2.31.1
On 12/07/21 9:55 pm, Stefan Berger wrote:
> From: Stefan Berger <[email protected]>
>
> When rngd is run as root then lots of these types of message will appear
> in the kernel log if the TPM has been configure to provide random bytes:
>
> [ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4
>
> The issue is caused by the following call that is interrupted while
> waiting for the TPM's response.
>
> sig = wait_event_interruptible(ibmvtpm->wq,
> !ibmvtpm->tpm_processing_cmd);
>
> The solution is to use wait_event() instead.
>
> To recreat the issue start rngd like this:
>
> sudo rngd -r /dev/hwrng -t
>
> Link: https://bugzilla.redhat.com/show_bug.cgi?id=1981473
> Fixes: 6674ff145eef ("tpm_ibmvtpm: properly handle interrupted packet receptions")
> Cc: Nayna Jain <[email protected]>
> Cc: George Wilson <[email protected]>
> Reported-by: Nageswara R Sastry <[email protected]>
> Signed-off-by: Stefan Berger <[email protected]>
Tested-by: Nageswara R Sastry <[email protected]>
> ---
> drivers/char/tpm/tpm_ibmvtpm.c | 13 ++++---------
> 1 file changed, 4 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
> index 903604769de9..99b0442a5fdf 100644
> --- a/drivers/char/tpm/tpm_ibmvtpm.c
> +++ b/drivers/char/tpm/tpm_ibmvtpm.c
> @@ -106,16 +106,13 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> {
> struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
> u16 len;
> - int sig;
>
> if (!ibmvtpm->rtce_buf) {
> dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
> return 0;
> }
>
> - sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
> - if (sig)
> - return -EINTR;
> + wait_event(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
>
> len = ibmvtpm->res_len;
>
> @@ -206,7 +203,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
> {
> struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
> bool retry = true;
> - int rc, sig;
> + int rc;
>
> if (!ibmvtpm->rtce_buf) {
> dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
> @@ -224,9 +221,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
> dev_info(ibmvtpm->dev,
> "Need to wait for TPM to finish\n");
> /* wait for previous command to finish */
> - sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
> - if (sig)
> - return -EINTR;
> + wait_event(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
> }
>
> spin_lock(&ibmvtpm->rtce_lock);
> @@ -551,7 +546,7 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
> /* len of the data in rtce buffer */
> ibmvtpm->res_len = be16_to_cpu(crq->len);
> ibmvtpm->tpm_processing_cmd = false;
> - wake_up_interruptible(&ibmvtpm->wq);
> + wake_up(&ibmvtpm->wq);
> return;
> default:
> return;
>
--
Thanks and Regards
R.Nageswara Sastry
On Mon, Jul 12, 2021 at 12:25:05PM -0400, Stefan Berger wrote:
> From: Stefan Berger <[email protected]>
>
> When rngd is run as root then lots of these types of message will appear
> in the kernel log if the TPM has been configure to provide random bytes:
>
> [ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4
>
> The issue is caused by the following call that is interrupted while
> waiting for the TPM's response.
>
> sig = wait_event_interruptible(ibmvtpm->wq,
> !ibmvtpm->tpm_processing_cmd);
>
> The solution is to use wait_event() instead.
Why?
/Jarkko
On 7/26/21 10:42 PM, Jarkko Sakkinen wrote:
> On Mon, Jul 12, 2021 at 12:25:05PM -0400, Stefan Berger wrote:
>> From: Stefan Berger <[email protected]>
>>
>> When rngd is run as root then lots of these types of message will appear
>> in the kernel log if the TPM has been configure to provide random bytes:
>>
>> [ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4
>>
>> The issue is caused by the following call that is interrupted while
>> waiting for the TPM's response.
>>
>> sig = wait_event_interruptible(ibmvtpm->wq,
>> !ibmvtpm->tpm_processing_cmd);
>>
>> The solution is to use wait_event() instead.
> Why?
So it becomes uninterruptible and these error messages go away.
Stefan
>
> /Jarkko
On Mon, Jul 26, 2021 at 11:00:51PM -0400, Stefan Berger wrote:
>
> On 7/26/21 10:42 PM, Jarkko Sakkinen wrote:
> > On Mon, Jul 12, 2021 at 12:25:05PM -0400, Stefan Berger wrote:
> > > From: Stefan Berger <[email protected]>
> > >
> > > When rngd is run as root then lots of these types of message will appear
> > > in the kernel log if the TPM has been configure to provide random bytes:
> > >
> > > [ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4
> > >
> > > The issue is caused by the following call that is interrupted while
> > > waiting for the TPM's response.
> > >
> > > sig = wait_event_interruptible(ibmvtpm->wq,
> > > !ibmvtpm->tpm_processing_cmd);
> > >
> > > The solution is to use wait_event() instead.
> > Why?
>
> So it becomes uninterruptible and these error messages go away.
We do not want to make a process uninterruptible. That would prevent
killing it.
/Jarkko
On 7/28/21 5:50 PM, Jarkko Sakkinen wrote:
> On Mon, Jul 26, 2021 at 11:00:51PM -0400, Stefan Berger wrote:
>> On 7/26/21 10:42 PM, Jarkko Sakkinen wrote:
>>> On Mon, Jul 12, 2021 at 12:25:05PM -0400, Stefan Berger wrote:
>>>> From: Stefan Berger <[email protected]>
>>>>
>>>> When rngd is run as root then lots of these types of message will appear
>>>> in the kernel log if the TPM has been configure to provide random bytes:
>>>>
>>>> [ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4
>>>>
>>>> The issue is caused by the following call that is interrupted while
>>>> waiting for the TPM's response.
>>>>
>>>> sig = wait_event_interruptible(ibmvtpm->wq,
>>>> !ibmvtpm->tpm_processing_cmd);
>>>>
>>>> The solution is to use wait_event() instead.
>>> Why?
>> So it becomes uninterruptible and these error messages go away.
> We do not want to make a process uninterruptible. That would prevent
> killing it.
I guess we'll have to go back to this one then:
https://www.spinics.net/lists/linux-integrity/msg16741.html
Stefan
>
> /Jarkko
On Thu, Jul 29, 2021 at 09:39:18AM -0400, Stefan Berger wrote:
>
> On 7/28/21 5:50 PM, Jarkko Sakkinen wrote:
> > On Mon, Jul 26, 2021 at 11:00:51PM -0400, Stefan Berger wrote:
> > > On 7/26/21 10:42 PM, Jarkko Sakkinen wrote:
> > > > On Mon, Jul 12, 2021 at 12:25:05PM -0400, Stefan Berger wrote:
> > > > > From: Stefan Berger <[email protected]>
> > > > >
> > > > > When rngd is run as root then lots of these types of message will appear
> > > > > in the kernel log if the TPM has been configure to provide random bytes:
> > > > >
> > > > > [ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4
> > > > >
> > > > > The issue is caused by the following call that is interrupted while
> > > > > waiting for the TPM's response.
> > > > >
> > > > > sig = wait_event_interruptible(ibmvtpm->wq,
> > > > > !ibmvtpm->tpm_processing_cmd);
> > > > >
> > > > > The solution is to use wait_event() instead.
> > > > Why?
> > > So it becomes uninterruptible and these error messages go away.
> > We do not want to make a process uninterruptible. That would prevent
> > killing it.
>
> I guess we'll have to go back to this one then:
> https://www.spinics.net/lists/linux-integrity/msg16741.html
Makes a heck lot more sense.
There's a typo in the commit message: PM_STATUS_BUSY
Also the commit message lacks explanation of this change completely:
@@ -690,8 +688,15 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
goto init_irq_cleanup;
}
- if (!strcmp(id->compat, "IBM,vtpm20")) {
+
+ if (!strcmp(id->compat, "IBM,vtpm20"))
chip->flags |= TPM_CHIP_FLAG_TPM2;
+
+ rc = tpm_get_timeouts(chip);
+ if (rc)
+ goto init_irq_cleanup;
+
+ if (chip->flags & TPM_CHIP_FLAG_TPM2) {
rc = tpm2_get_cc_attrs_tbl(chip);
The last paragraph should be rewritten in imperative form.
Finally, you could simplify the fix by simply changing the type of
tpm_processing_cmd to u8, and just set it to 'true' and 'false',
which will set the first bit.
/Jarkko
On 7/29/21 8:57 PM, Jarkko Sakkinen wrote:
> On Thu, Jul 29, 2021 at 09:39:18AM -0400, Stefan Berger wrote:
>> On 7/28/21 5:50 PM, Jarkko Sakkinen wrote:
>>> On Mon, Jul 26, 2021 at 11:00:51PM -0400, Stefan Berger wrote:
>>>> On 7/26/21 10:42 PM, Jarkko Sakkinen wrote:
>>>>> On Mon, Jul 12, 2021 at 12:25:05PM -0400, Stefan Berger wrote:
>>>>>> From: Stefan Berger <[email protected]>
>>>>>>
>>>>>> When rngd is run as root then lots of these types of message will appear
>>>>>> in the kernel log if the TPM has been configure to provide random bytes:
>>>>>>
>>>>>> [ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4
>>>>>>
>>>>>> The issue is caused by the following call that is interrupted while
>>>>>> waiting for the TPM's response.
>>>>>>
>>>>>> sig = wait_event_interruptible(ibmvtpm->wq,
>>>>>> !ibmvtpm->tpm_processing_cmd);
>>>>>>
>>>>>> The solution is to use wait_event() instead.
>>>>> Why?
>>>> So it becomes uninterruptible and these error messages go away.
>>> We do not want to make a process uninterruptible. That would prevent
>>> killing it.
>> I guess we'll have to go back to this one then:
>> https://www.spinics.net/lists/linux-integrity/msg16741.html
> Makes a heck lot more sense.
>
> There's a typo in the commit message: PM_STATUS_BUSY
>
> Also the commit message lacks explanation of this change completely:
>
> @@ -690,8 +688,15 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
> goto init_irq_cleanup;
> }
>
> - if (!strcmp(id->compat, "IBM,vtpm20")) {
> +
> + if (!strcmp(id->compat, "IBM,vtpm20"))
> chip->flags |= TPM_CHIP_FLAG_TPM2;
> +
> + rc = tpm_get_timeouts(chip);
> + if (rc)
> + goto init_irq_cleanup;
> +
> + if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> rc = tpm2_get_cc_attrs_tbl(chip);
>
> The last paragraph should be rewritten in imperative form.
will fix.
>
> Finally, you could simplify the fix by simply changing the type of
> tpm_processing_cmd to u8, and just set it to 'true' and 'false',
> which will set the first bit.
Are you sure? It's a bit mask we are using this with. Using 'true' for
these type of operations doesn't sound right.
u8 status = chip->ops->status(chip);
if ((status & chip->ops->req_complete_mask) ==
chip->ops->req_complete_val)
goto out_recv;
https://elixir.bootlin.com/linux/latest/source/drivers/char/tpm/tpm-interface.c#L108
@@ -457,7 +455,7 @@ static const struct tpm_class_ops tpm_ibmvtpm = {
.send = tpm_ibmvtpm_send,
.cancel = tpm_ibmvtpm_cancel,
.status = tpm_ibmvtpm_status,
- .req_complete_mask = 0,
+ .req_complete_mask = TPM_STATUS_BUSY,
.req_complete_val = 0,
.req_canceled = tpm_ibmvtpm_req_canceled,
};
Stefan
>
> /Jarkko