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Add an ioctl if you need to be able to retrieve > that info. Yeah the problem is an IOCTL is even worse from the security pov. This is for an tool which doesn't have access to the file descriptor which provides that information. So using pidfd_getfd() or similar to get the FD and then call an IOCTL on it would be a security violation. The real question is how should we make this information public available in the system? Regards, Christian.