Re: Trouble with ptrace self-attach rule since kernel > 2.6.14

From: Andreas Hobein
Date: Mon Sep 04 2006 - 11:53:46 EST


On Monday 04 September 2006 17:23, you wrote:
> Could you test your application with 2.6.18-rc6 and this change
>
> - if (task == current)
> + if (task->tgid == current->tgid)
>
> reverted? I think any report, positive or negative, would be useful.

In fact I applied exactly this change before posting to this mailing list to
kernel-2.6.17-1.2174_FC5 (Source rpm from fedora core 5) _without_ success.
Thats why I thought there were also some other changes with similar effects
in the kernel source at the same time.

> It would be nice if your test covers different conditions, such as
> 'main thread debugs sub-thread' and vice versa. Exec under ptrace is
> also interesting.

In my application a child thread debugs sibling threads and the parent.
Neither works for newer kernels.

I will try a 2.6.18-rc6 vanilla kernel with the above patch applied at home
and give you some feedback wether there is a different result as with the
patched 2.6.17-1.2174_FC5 kernel.

> It's a pity to disappoint you, but you may be the 3rd :) Found this
> unanswered message:
>
> http://marc.theaimsgroup.com/?l=linux-kernel&m=114073955827139

May be there are more advocates of self-debugging than expected ...

Andreas
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