Using strace with linux-inject

[Aakash16]

Thanks for creating awesome injection library. I am able to successfully inject with help of your technique. But when I run sample-target with strace the injection fails with message: ptrace(PTRACE_ATTACH) failed
please help.

[gaffe23]

Unfortunately, trying to run sample-target under strace presents a bit of a chicken-and-egg problem.

strace works by attaching to the target application using ptrace. However, linux-inject itself also needs to be able to attach to the target application using ptrace. Two processes cannot ptrace the same application at the same time, so linux-inject can't attach when strace is already attached.

As a result, you can't use linux-inject on an application that is running under strace.

[Aakash16]

Thank you for your reply. Now I understand the problem.

On 2/17/16, gaffe23 [email protected] wrote:

Unfortunately, trying to run sample-target under strace presents a bit
of a chicken-and-egg problem.

strace works by attaching to the target application using ptrace.
However, linux-inject itself also needs to be able to attach to the target
application using ptrace. Two processes cannot ptrace the same
application at the same time, so linux-inject can't attach when strace
is already attached.

As a result, you can't use linux-inject on an application that is running
under strace.

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