lkml.org 
[lkml]   [2011]   [Apr]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/5] ptrace: Prepare to fix racy accesses on task breakpoints
On Wed, Apr 13, 2011 at 03:34:18PM +0100, Will Deacon wrote:
> > Returning -ERSCH there would mean that the task struct doesn't exist,
> > or something confusing like this. Which is not true: the task exists.
>
> Sure, we need a way of saying `you can't take a reference to the
> breakpoints for this task' without specifying why. So I guess -ESRCH is
> wrong but I don't know that -1 is correct either (then again, I'm not
> *too* bothered by it :).

-EBUSY perhaps? Well I took -1 by default...

>
> > OTOH, the caller, which is ptrace, needs to take a decision when he
> > can't take a reference to the breakpoints. The behaviour is
> > to act as if the process does not exist anymore, which is about to
> > happen for real but we anticipate because the task has reached a
> > state in its exiting path where we can't manipulate the breakpoints
> > anymore.
> >
> > So the rationale behind it is that -ERSCH is an interpretation
> > of the caller.
> >
> > Right?
>
> Yup.
>
> For this and the ARM patch:
>
> Acked-by: Will Deacon <will.deacon@arm.com>

Great! Thanks!


\
 
 \ /
  Last update: 2011-04-13 17:13    [W:0.073 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site