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

[Oleg Nesterov <oleg@tv-sign.ru>]

On 09/04, Andreas Hobein wrote:
>
> Thank you all for your kind assistance. It turned out that using vfork() or 
> clone() would make a considerable redesign of my code necessary. While the 
> added overhead from a "real" fork plus communication of the result over pipes 
> is still acceptable, I currently have a lack of time to restructure my 
> application to work with vfork or clone and its intrinsic restrictions. Also 
> some more non-portable code would be added, which discourages me a bit also.

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.

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.

> Since I'm rather clueless with regard to the kernel internals I'm afraid I 
> can't add more value to this discussion other than to prove there is at least 
> a second application out there being affected by this patch.

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

(the author cc'ed)

Oleg.