From: Lino Sanfilippo <l.sanfilippo@kunbus.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de>,
peterhuewe@gmx.de, jarkko@kernel.org, stefanb@linux.vnet.ibm.com,
James.Bottomley@hansenpartnership.com, stable@vger.kernel.org,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/2] tpm: fix reference counting for struct tpm_chip
Date: Fri, 5 Feb 2021 16:50:13 +0100 [thread overview]
Message-ID: <f6e5dd7d-30df-26d9-c712-677c127a8026@kunbus.com> (raw)
In-Reply-To: <20210205151511.GM4718@ziepe.ca>
On 05.02.21 16:15, Jason Gunthorpe wrote:
>
> No, the cdev layer holds the refcount on the device while open is
> being called.
>
> Jason
>
Yes, but the reference that is responsible for the chip deallocation is chip->dev
which is linked to chip->cdev and represents /dev/tpm, not /dev/tpmrm.
You are right, we dont have the issue with /dev/tpm for the reason you mentioned.
But /dev/tpmrm is represented by chip->cdevs and keeping this ref held by the cdev
layer wont protect us from the chip being freed (which is the reason why we need
the chip->dev reference in the first place).
And yes, the naming dev/devs/cdev/cdevs is quite confusing :(
Regards,
Lino
next prev parent reply other threads:[~2021-02-05 16:15 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-04 23:50 [PATCH v3 0/2] TPM fixes Lino Sanfilippo
2021-02-04 23:50 ` [PATCH v3 1/2] tpm: fix reference counting for struct tpm_chip Lino Sanfilippo
2021-02-05 0:46 ` Stefan Berger
2021-02-05 1:44 ` Stefan Berger
2021-02-05 2:01 ` James Bottomley
2021-02-05 10:52 ` Lino Sanfilippo
2021-02-05 13:29 ` Stefan Berger
2021-02-05 10:34 ` Lino Sanfilippo
2021-02-05 6:50 ` Greg KH
2021-02-05 13:05 ` Jason Gunthorpe
2021-02-05 14:55 ` Lino Sanfilippo
2021-02-05 15:15 ` Jason Gunthorpe
2021-02-05 15:50 ` Lino Sanfilippo [this message]
2021-02-05 15:58 ` Jason Gunthorpe
2021-02-05 21:50 ` Lino Sanfilippo
2021-02-06 0:39 ` Jason Gunthorpe
2021-02-04 23:50 ` [PATCH v3 2/2] tpm: in tpm2_del_space check if ops pointer is still valid Lino Sanfilippo
2021-02-05 0:34 ` James Bottomley
2021-02-05 2:18 ` Jarkko Sakkinen
2021-02-05 16:48 ` James Bottomley
2021-02-05 17:25 ` Jason Gunthorpe
2021-02-05 17:54 ` James Bottomley
2021-02-06 1:02 ` Jason Gunthorpe
2021-02-06 1:08 ` James Bottomley
2021-02-06 1:34 ` Jason Gunthorpe
2021-02-09 11:52 ` Lino Sanfilippo
2021-02-09 13:36 ` Jason Gunthorpe
2021-02-09 13:39 ` Lino Sanfilippo
2021-02-12 11:02 ` Jarkko Sakkinen
2021-02-12 10:59 ` Jarkko Sakkinen
2021-02-14 17:22 ` Lino Sanfilippo
2021-02-05 10:30 ` Lino Sanfilippo
2021-03-06 16:07 ` Lino Sanfilippo
2021-02-05 6:51 ` Greg KH
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