ceph daemons DUMPABLE flag is cleared by setuid preventing coredumps
I observed while using ceph-ansible on Linode that ceph daemons would not produce coredumps. This was caused by the DUMPABLE flag being cleared by prctl. From prctl(2):
PR_SET_DUMPABLE (since Linux 2.3.20) ... Normally, this flag is set to 1. However, it is reset to the current value contained in the file /proc/sys/fs/suid_dumpable (which by default has the value 0), in the fol‐ lowing circumstances: * The process's effective user or group ID is changed. * The process's filesystem user or group ID is changed (see credentials(7)). * The process executes (execve(2)) a set-user-ID or set-group-ID program, or a program that has capabilities (see capabilities(7)).
I have a patch ready to submit after creating this issue.