lkml.org 
[lkml]   [2007]   [Jan]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] namespaces: fix race at task exit
On 01/25, Serge E. Hallyn wrote:
>
> In do_exit(), the exit_task_namespaces() was placed after
> exit_notify() because exit_notify ends up using the pid
> namespace both to access the reaper, and for detaching the
> pid. However, this placement allows an nfs server to reap
> the task before exit_task_namespaces() completes.
>
> This patch moves the exit_task_namespaces() into release_task,
> below release_thread() which puts the pids(), and just above
> the call_rcu(delayed_put_task_struct). I believe this should
> solve both problems.
>
> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
>
> ---
>
> kernel/exit.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> 765277a4170d7bbd1c4613de661ec6ac64d5580a
> diff --git a/kernel/exit.c b/kernel/exit.c
> index 3540172..ab9ae30 100644
> --- a/kernel/exit.c
> +++ b/kernel/exit.c
> @@ -174,6 +174,7 @@ repeat:
> write_unlock_irq(&tasklist_lock);
> proc_flush_task(p);
> release_thread(p);
> + exit_task_namespaces(p);
> call_rcu(&p->rcu, delayed_put_task_struct);

Probably I missed some other patches in this area, but I can't understand
this fix.

With this change we are doing __put_mnt_ns() when we surely don't have ->sighand,
no? Could you please explain?

Oleg.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-01-25 17:43    [W:0.158 / U:0.456 seconds]
©2003-2014 Jasper Spaans. Advertise on this site