Messages in this thread | | | Subject | Re: [PATCH v3 1/2] tpm: fix reference counting for struct tpm_chip | From | Lino Sanfilippo <> | Date | Fri, 5 Feb 2021 16:50:13 +0100 |
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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
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