I have a server application that can be summoned for the client using inetd. However, if I try to attach to the server process that was launched with inetd, I get the following response: ptrace: Operation not permitted.
gdb --annotate=3 /my/app/here <processId>
Current directory is /usr/local/bin/
GNU gdb 6.8
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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This GDB was configured as "i686-pc-linux-gnu"...
Reading symbols from /usr/local/bin/flumed...done.
Using host libthread_db library "/lib/tls/libthread_db.so.1".
Attaching to program: /my/app/here, process <processId>
ptrace: Operation not permitted.
/usr/local/bin/<processId>: No such file or directory.
(gdb)
Solution for me was this:
echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope