In a project, I'm using the DriverKit(and HIDDriverKit) framework. I have encountered a problem in the connection between the client app and the driver, which is implemented by the "IOKit" framework. By calling the function "IOServiceGetMatchingServices" the value of "iterator" returns correctly and then communication with the driver is done. However, after releasing the version on the TestFlight, on some systems, the value of the "iterator" returned 0 and it is not possible to communicate with the driver. I checked the status of the activated driver with the command "systemextensionsctl list" and there are no problems on the driver side and the values of "Enabled" and "Active" are starred. AppSandbox = True, SIP: enable ret = IOServiceGetMatchingServices(kIOMainPortDefault, IOServiceNameMatching(dextIdentifier), &iterator); if (ret != kIOReturnSuccess) { goto fail; } while ((service = IOIteratorNext(iterator)) != IO_OBJECT_NULL) { ret = IOServiceOpen(service, mach_task_self(), 0, &connection); if(ret == kIOReturnSuccess) { break; } else { syslog(LOG_WARNING, "IDmelonLog LIB: Can't open service"); } IOObjectRelease(service); }

I am currently in the process of developing a DEXT for a USB based external mass storage device using the USBDriverKit framework. IOUSBHostInterface is used as the provider to communicate with the interface's endpoints and I am successful in it. As per the IOUSBHostInterface documentation, To use a host interface object, call Open to create a new session between the interface and your driver. After successfully opening your session, you can request information from the interface and set up pipes to communicate with the interface's endpoints. Remember to close the session you opened in the Stop method of your driver. However, calling Open gains exclusive access to the USB interface and does not allow other services to access the interface. Also, to let go of the exclusive access, Close method can be called but in the Stop method which is called only once during the lifecycle of the extension (when the DEXT is unloaded). As a result of this, Apple's mass storage related KEXTs (media and partition related specifically) do not match the interface and so the filesystem of the drive in question does not get mounted whenever the DEXT has matched the interface. Is this exclusive access a limitation of USBDriverkit or is there any way to get around this issue in this case?