View Full Version : Ubuntu Security Feature affects Replay Engine

08-09-2008, 06:53 AM
A security feature intended to prevent process hijacking can interfere with debugging.


This feature was introduced in Ubuntu 10.10 and interferes with the ptrace attach command. It prevents attaching to a running process if the child was not directly started up under debugger control. ReplayEngine forks off a number of copies of the program and fails into this security area. A short term fix is to become root and do

“echo 0 > /proc/sys/kernel/yama/ptrace_scope”

In TotalView, if you try this on a system which has not had the ptrace_scope changed, and Replay Engine is enabled, you will see a crash and near the top of where the debugger starts dumping diagnostics messages, you will see line that says something like:

client/client.c:17015:client_main [2808:2808]: proc_ptrace_attach_threads failed