On Tue 23-08-16 18:32:34, Oleg Nesterov wrote:
> On 08/23, Michal Hocko wrote:
> >
> > --- a/kernel/fork.c
> > +++ b/kernel/fork.c
> > @@ -913,14 +913,11 @@ void mm_release(struct task_struct *tsk, struct
> > mm_struct *mm)
> > deactivate_mm(tsk, mm);
> >
> > /*
> > - * If we're exiting normally, clear a user-space tid field if
> > - * requested. We leave this alone when dying by signal, to leave
> > - * the value intact in a core dump, and to save the unnecessary
> > - * trouble, say, a killed vfork parent shouldn't touch this mm.
> > - * Userland only wants this done for a sys_exit.
> > + * Signal userspace if we're not exiting with a core dump
> > + * or a killed vfork parent which shouldn't touch this mm.
>
> Well. ACK, but the comment looks wrong...
>
> The "killed vfork parent ..." part should be removed, as you pointed
> out this is no longer true.
>
> OTOH, to me it would be better to not remove the "leave the value
> intact in a core dump" part, otherwise the " we're not exiting with
> a core dump" looks pointless because SIGNAL_GROUP_COREDUMP is self-
> documenting.
Sounds better?
diff --git a/kernel/fork.c b/kernel/fork.c
index b89f0eb99f0a..ddde5849df81 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -914,7 +914,8 @@ void mm_release(struct task_struct *tsk, struct mm_struct
*mm)
/*
* Signal userspace if we're not exiting with a core dump
- * or a killed vfork parent which shouldn't touch this mm.
+ * because we want to leave the value intact for debugging
+ * purposes.
*/
if (tsk->clear_child_tid) {
if (!(tsk->signal->flags & SIGNAL_GROUP_COREDUMP) &&
--
Michal Hocko
SUSE Labs
