From: Hans de Goede <hdegoede@redhat.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: linux-integrity@vger.kernel.org, stable@vger.kernel.org,
Peter Huewe <peterhuewe@gmx.de>, Jason Gunthorpe <jgg@ziepe.ca>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tpm/tpm_tis: Free IRQ if probing fails
Date: Tue, 14 Apr 2020 10:26:32 +0200 [thread overview]
Message-ID: <d6684575-ce91-fe72-6035-11834a05cd54@redhat.com> (raw)
In-Reply-To: <20200414071349.GA8403@linux.intel.com>
Hi,
On 4/14/20 9:13 AM, Jarkko Sakkinen wrote:
> On Mon, Apr 13, 2020 at 08:11:15PM +0200, Hans de Goede wrote:
>> Hi,
>>
>> On 4/13/20 8:07 PM, Jarkko Sakkinen wrote:
>>> On Mon, Apr 13, 2020 at 12:04:25PM +0200, Hans de Goede wrote:
>>>> Hi Jarkko,
>>>>
>>>> On 4/12/20 7:04 PM, Jarkko Sakkinen wrote:
>>>>> Call devm_free_irq() if we have to revert to polling in order not to
>>>>> unnecessarily reserve the IRQ for the life-cycle of the driver.
>>>>>
>>>>> Cc: stable@vger.kernel.org # 4.5.x
>>>>> Reported-by: Hans de Goede <hdegoede@redhat.com>
>>>>> Fixes: e3837e74a06d ("tpm_tis: Refactor the interrupt setup")
>>>>> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
>>>>> ---
>>>>> drivers/char/tpm/tpm_tis_core.c | 5 ++++-
>>>>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
>>>>> index 27c6ca031e23..ae6868e7b696 100644
>>>>> --- a/drivers/char/tpm/tpm_tis_core.c
>>>>> +++ b/drivers/char/tpm/tpm_tis_core.c
>>>>> @@ -1062,9 +1062,12 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>>>> if (irq) {
>>>>> tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
>>>>> irq);
>>>>> - if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
>>>>> + if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
>>>>> dev_err(&chip->dev, FW_BUG
>>>>> "TPM interrupt not working, polling instead\n");
>>>>> + devm_free_irq(chip->dev.parent, priv->irq,
>>>>> + chip);
>>>>> + }
>>>>
>>>> My initial plan was actually to do something similar, but if the probe code
>>>> is actually ever fixed to work as intended again then this will lead to a
>>>> double free as then the IRQ-test path of tpm_tis_send() will have called
>>>> disable_interrupts() which already calls devm_free_irq().
>>>>
>>>> You could check for chip->irq != 0 here to avoid that.
Erm in case you haven't figured it out yet this should be priv->irq != 0, sorry.
>>>>
>>>> But it all is rather messy, which is why I went with the "#if 0" approach
>>>> in my patch.
>>>
>>> I think it is right way to fix it. It is a bug independent of the issue
>>> we are experiencing.
>>>
>>> However, what you are suggesting should be done in addition. Do you have
>>> a patch in place or do you want me to refine mine?
>>
>> I do not have a patch ready for this, if you can refine yours that would
>> be great.
>
> Thanks! Just wanted to confirm.
And thank you for working on a (temporary?) fix for this.
Regards,
Hans
next prev parent reply other threads:[~2020-04-14 8:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-12 17:04 [PATCH] tpm/tpm_tis: Free IRQ if probing fails Jarkko Sakkinen
2020-04-13 10:04 ` Hans de Goede
2020-04-13 18:07 ` Jarkko Sakkinen
2020-04-13 18:11 ` Hans de Goede
2020-04-14 7:13 ` Jarkko Sakkinen
2020-04-14 8:26 ` Hans de Goede [this message]
2020-04-14 16:04 ` Jarkko Sakkinen
2020-04-14 16:45 ` Jarkko Sakkinen
2020-04-14 17:15 ` Hans de Goede
2020-04-16 13:13 ` Jarkko Sakkinen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d6684575-ce91-fe72-6035-11834a05cd54@redhat.com \
--to=hdegoede@redhat.com \
--cc=arnd@arndb.de \
--cc=gregkh@linuxfoundation.org \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jgg@ziepe.ca \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterhuewe@gmx.de \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).