Re: [PATCH v3 1/2] tee: optee: Fix supplicant based device enumeration

[Jan Kiszka]

On 02.11.23 08:37, Sumit Garg wrote:
> On Tue, 31 Oct 2023 at 17:14, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
>>
>> On 31.10.23 12:04, Jerome Forissier wrote:
>>>
>>>
>>> On 10/30/23 16:59, Sumit Garg wrote:
>>>> Currently supplicant dependent optee device enumeration only registers
>>>> devices whenever tee-supplicant is invoked for the first time. But it
>>>> forgets to remove devices when tee-supplicant daemon stops running and
>>>> closes its context gracefully. This leads to following error for fTPM
>>>> driver during reboot/shutdown:
>>>>
>>>> [   73.466791] tpm tpm0: ftpm_tee_tpm_op_send: SUBMIT_COMMAND invoke error: 0xffff3024
>>>>
>>>> Fix this by separating supplicant dependent devices so that the
>>>> user-space service can detach supplicant devices before closing the
>>>> supplicant.
>>>>
>>>> Reported-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>>>> Link: https://github.com/OP-TEE/optee_os/issues/6094
>>>> Fixes: 5f178bb71e3a ("optee: enable support for multi-stage bus enumeration")
>>>> Tested-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>>>> Tested-by: Masahisa Kojima <masahisa.kojima@xxxxxxxxxx>
>>>> Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
>>>> ---
>>>>  drivers/tee/optee/device.c | 13 ++++++++++---
>>>>  1 file changed, 10 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
>>>> index 64f0e047c23d..78fc0a15c463 100644
>>>> --- a/drivers/tee/optee/device.c
>>>> +++ b/drivers/tee/optee/device.c
>>>> @@ -60,9 +60,10 @@ static void optee_release_device(struct device *dev)
>>>>      kfree(optee_device);
>>>>  }
>>>>
>>>> -static int optee_register_device(const uuid_t *device_uuid)
>>>> +static int optee_register_device(const uuid_t *device_uuid, u32 func)
>>>>  {
>>>>      struct tee_client_device *optee_device = NULL;
>>>> +    const char *dev_name_fmt = NULL;
>>>>      int rc;
>>>>
>>>>      optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
>>>> @@ -71,7 +72,13 @@ static int optee_register_device(const uuid_t *device_uuid)
>>>>
>>>>      optee_device->dev.bus = &tee_bus_type;
>>>>      optee_device->dev.release = optee_release_device;
>>>> -    if (dev_set_name(&optee_device->dev, "optee-ta-%pUb", device_uuid)) {
>>>> +
>>>> +    if (func == PTA_CMD_GET_DEVICES_SUPP)
>>>> +            dev_name_fmt = "optee-ta-supp-%pUb";
>>>> +    else
>>>> +            dev_name_fmt = "optee-ta-%pUb";
>>>
>>> That's an ABI change, isn't it?
>>
> 
> Indeed it is an ABI break although we would like this to be backported
> but don't want to break existing users. So I brainstormed on it and
> came up with an alternative fix via device attribute in v4. Please
> have a look.
> 
>> Oh, here did this come from! Yes, I recently had to adjust some systemd
>> service due to carrying this patch but looking for the change only in
>> upstream:
>>
>> https://github.com/ilbers/isar/commit/83644ddf694e51f11793e6107e4aaf68dc0043a5
>>
> 
> You don't need to unbind all of the optee devices. v4 would help you
> to maintain backwards compatibility, can you retest it?

How do I know from tee-supplicant perspective which devices I need to
unbind? There could be one in the future that will also use storage and
will therefore also fail once the supplicant is gone.

Jan

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