From: Anton Arapov <aarapov@redhat.com>
Date: Tue, 9 Sep 2008 09:47:19 +0200
Subject: Revert [misc] fix wrong test in wait_task_stopped
Message-id: 20080909074719.GC3417@redhat.com
O-Subject: Re: [RHEL5.3 Patch] BZ382161: fix wrong test in wait_task_stopped()
Bugzilla: 382211

* correct bugzilla 382211

  rhel5 is not vulnerable by 382211 and patch is address a wrong test.
  Don, please drop/revert the patch.

  The concern is to not commit needless patches to the kernel.

-- Anton

Jerome Marchand wrote:
> Bugzilla:
> https://bugzilla.redhat.com/show_bug.cgi?id=382161
>
> Description:
> There is a wrong test in wait_task_stopped().
> There was an old (p->state > TASK_STOPPED) test which used to mean not
> dead (that was before TASK_TRACED and exit_state existed). Then, it
> has been misunderstood as a wrong check of TASK_TRACED bit (commit
> 14bf01bb0599c89fc7f426d20353b76e12555308).
> I'm not sure there is an actual bug on rhel5, but that test is very
> wrong.
>
> Upstream status:
> commit a3474224e6a01924be40a8255636ea5522c1023a
>
> Brew build:
> http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1413558
>
> Test status:
> Build on all archs, booted on i686.
>
> Regards,
> Jerome Marchand
>
> ---
>  kernel/exit.c |    3 +--
>  1 files changed, 1 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/exit.c b/kernel/exit.c
> index 45a1562..0b93d68 100644
> --- a/kernel/exit.c
> +++ b/kernel/exit.c
> @@ -1225,8 +1225,7 @@ static int wait_task_stopped(struct task_struct
> *p, int delayed_group_leader,
>       uid_t uid = p->uid;
>
>       exit_code = p->exit_code;
> -     if (unlikely(!exit_code) ||
> -         unlikely(p->state & TASK_TRACED))
> +     if (unlikely(!exit_code) || unlikely(p->exit_state))
>           goto bail_ref;
>       return wait_noreap_copyout(p, pid, uid, CLD_STOPPED,
>                      (exit_code << 8) | 0x7f,
>

diff --git a/kernel/exit.c b/kernel/exit.c
index f8a00ec..db61e3f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1253,7 +1253,8 @@ static int wait_task_stopped(struct task_struct *p, int delayed_group_leader,
 		uid_t uid = p->uid;
 
 		exit_code = p->exit_code;
-		if (unlikely(!exit_code) || unlikely(p->exit_state))
+		if (unlikely(!exit_code) ||
+		    unlikely(p->state & TASK_TRACED))
 			goto bail_ref;
 		return wait_noreap_copyout(p, pid, uid, CLD_STOPPED,
 					   (exit_code << 8) | 0x7f,