Troubleshoot attaching to processes using GDB

Attaching to a process on Linux with GDB as a normal user may fail with "ptrace:Operation not permitted". By default Linux does not allow attaching to a process which wasn't launched by the debugger (see the Yama security documentation for more details).

There are two ways to workaround this:

• Run the following command as super user: echo "0" > /proc/sys/kernel/yama/ptrace_scope

  This will set the ptrace level to 0, after this just with user permissions you can attach to processes which are not launched by the debugger.

• Alternatively, launch GDB as super user and attach to processes.