Re: [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct
flat view
From: Oleg Nesterov <hidden>
Date: 2017-04-05 16:25:58
Also in:
lkml
Possibly related (same subject, not in this thread)
- 2017-04-05 · Re: [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct · Oleg Nesterov <oleg@redhat.com>
- 2017-04-05 · Re: [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct · Eric W. Biederman <hidden>
On 04/02, Eric W. Biederman wrote:
quoted hunk ↗ jump to hunk
--- a/kernel/fork.c +++ b/kernel/fork.c@@ -1515,6 +1515,13 @@ static __latent_entropy struct task_struct *copy_process( if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND)) return ERR_PTR(-EINVAL); + /* Disallow CLONE_THREAD with a shared SIGHAND structure. No + * one cares
Well, can't resists... I won't argue, but we can't know if no one cares or not. I agree that most probably this won't break something, but who knows... I am always scared when we add the incompatible changes.
and supporting it leads to unnecessarily complex + * code. + */ + if ((clone_flags & CLONE_THREAD) && (atomic_read(¤t->sighand->count) > 1)) + return ERR_PTR(-EINVAL);
Perhaps the comment should explain why we do this and say that sighand-unsharing in de_thread() depends on this. Oleg.