UST consumer daemon should handle SIGBUS
There is an issue with the security model of lib ring buffer (lttng-ust) vs SIGBUS handling by consumer daemon. We do not trap SIGBUS in the consumer daemon. An application using ftruncate on a ring buffer shm could cause the consumer to be killed with SIGBUS.
Updated by Mathieu Desnoyers 5 months ago
One possible way to solve this would be to use memfd and fcntl(2) F_ADD_SEALS (only available since Linux 3.17). It would not however cover kernels older than 3.17 (which we support) and would not work for --shm-path, because it only works for memfd.
So handling SIGBUS in the consumer daemon seems like a better approach to solve this.