Re: [PATCH v4 1/2] tee: optee: Fix supplicant based device enumeration

Hi Sumit,

On Thu, 2 Nov 2023 at 09:31, Sumit Garg sumit.garg@linaro.org 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 adding an attribute for supplicant dependent devices so that the user-space service can detect and detach supplicant devices before closing the supplicant:

$ for dev in /sys/bus/tee/devices/*; do if [[ -f "$dev/need_supplicant" && -f "$dev/driver/unbind" ]]; \ then echo $(basename "$dev") > $dev/driver/unbind; fi done

Reported-by: Jan Kiszka jan.kiszka@siemens.com Link: https://github.com/OP-TEE/optee_os/issues/6094 Fixes: 5f178bb71e3a ("optee: enable support for multi-stage bus enumeration") Signed-off-by: Sumit Garg sumit.garg@linaro.org

---

.../ABI/testing/sysfs-bus-optee-devices | 9 +++++++++ drivers/tee/optee/device.c | 17 +++++++++++++++-- 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-optee-devices b/Documentation/ABI/testing/sysfs-bus-optee-devices index 0f58701367b6..d914f6629662 100644 --- a/Documentation/ABI/testing/sysfs-bus-optee-devices +++ b/Documentation/ABI/testing/sysfs-bus-optee-devices @@ -6,3 +6,12 @@ Description: OP-TEE bus provides reference to registered drivers under this directory. The <uuid> matches Trusted Application (TA) driver and corresponding TA in secure OS. Drivers are free to create needed API under optee-ta-<uuid> directory.

+What: /sys/bus/tee/devices/optee-ta-<uuid>/need_supplicant +Date: July 2008

nit, date needs changing

+KernelVersion: 6.7 +Contact: op-tee@lists.trustedfirmware.org +Description:

•           Allows to distinguish whether an OP-TEE based TA/device requires user-space
  

•           tee-supplicant to function properly or not. This attribute will be present for
  

•           devices which depend on tee-supplicant to be running.
  

diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c index 64f0e047c23d..4b1092127694 100644 --- a/drivers/tee/optee/device.c +++ b/drivers/tee/optee/device.c @@ -60,7 +60,16 @@ static void optee_release_device(struct device *dev) kfree(optee_device); }

-static int optee_register_device(const uuid_t *device_uuid) +static ssize_t

(struct device *dev,

•                               struct device_attribute *attr,
  

•                               char *buf)
  

+{

•   return 0;
  

+}

+static DEVICE_ATTR_RO(need_supplicant);

+static int optee_register_device(const uuid_t *device_uuid, u32 func) { struct tee_client_device *optee_device = NULL; int rc; @@ -83,6 +92,10 @@ static int optee_register_device(const uuid_t *device_uuid) put_device(&optee_device->dev); }

•   if (func == PTA_CMD_GET_DEVICES_SUPP)
  

•           device_create_file(&optee_device->dev,
  

•                              &dev_attr_need_supplicant);
  

•   return rc;
  

}

@@ -142,7 +155,7 @@ static int __optee_enumerate_devices(u32 func) num_devices = shm_size / sizeof(uuid_t);

    for (idx = 0; idx < num_devices; idx++) {

•           rc = optee_register_device(&device_uuid[idx]);
  

•           rc = optee_register_device(&device_uuid[idx], func);
            if (rc)
                    goto out_shm;
    }
  

-- 2.34.1

Other than that Reviewed-by: Ilias Apalodimas ilias.apalodimas@linaro.org