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Comment by _kst_ | Hacker News Reader

I tried this on Ubuntu 22.04.1 and got an error:

    $ reptyr 10330                                                                                                                                                
    Unable to attach to pid 10330: Operation not permitted 
    The kernel denied permission while attaching. If your uid matches
    the target's, check the value of /proc/sys/kernel/yama/ptrace_scope.
    For more information, see /etc/sysctl.d/10-ptrace.conf
    $

I haven't (yet) looked into how to fix or work around this problem.

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Either, as root:

# echo 0 > /proc/sys/kernel/yama/ptrace_scope

or permanently by editing the file /etc/sysctl.d/10-ptrace.conf

What are the costs and / or downsides to enabling prace_scope?

https://askubuntu.com/a/153970

> What are the risks in setting ptrace_scope to 0?

> - This restores the old behavior where one process can "trace" another process, even if there is no parent-child relationship.

> - In theory, a piece of malware can use this to harm you/your computer; e.g. it can attach to Firefox and log all of your URLs/passwords, etc. In practice this is extremely unlikely unless you blindly install binary debs from random sites, etc.

> - As far as debugging goes, the 0 settings is in fact required for gdb, strace, etc. to attach to non-children unless you run them with elevated privileges (sudo).

were you root?

No, I wasn't root.

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