lkml.org 
[lkml]   [2009]   [Jul]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] Disable CLONE_PARENT for init

Disable CLONE_PARENT for init.

When global or container-init processes use CLONE_PARENT, they create a
multi-rooted process tree. Besides siblings of global init remain as
zombies on exit since they are not reaped by their parent (swapper). So
prevent global and container-inits from creating siblings.

Changelog[v3]:
- [Roland, Oleg] Simplify comment describing the change
Changelog[v2]:
- Simplify patch description based on comments from Eric Biederman
and Oleg Nesterov.
- [Oleg Nesterov] Use SIGNAL_UNKILLABLE instead of is_global_init()

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Roland McGrath <roland@redhat.com>
---
kernel/fork.c | 10 ++++++++++
1 file changed, 10 insertions(+)

Index: linux-mmotm/kernel/fork.c
===================================================================
--- linux-mmotm.orig/kernel/fork.c 2009-07-16 10:03:01.000000000 -0700
+++ linux-mmotm/kernel/fork.c 2009-07-16 11:36:28.000000000 -0700
@@ -992,6 +992,16 @@
if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
return ERR_PTR(-EINVAL);

+ /*
+ * Siblings of global init remain as zombies on exit since they are
+ * not reaped by their parent (swapper). To solve this and to avoid
+ * multi-rooted process trees, prevent global and container-inits
+ * from creating siblings.
+ */
+ if ((clone_flags & CLONE_PARENT) &&
+ current->signal->flags & SIGNAL_UNKILLABLE)
+ return ERR_PTR(-EINVAL);
+
retval = security_task_create(clone_flags);
if (retval)
goto fork_out;

\
 
 \ /
  Last update: 2009-07-28 18:39    [W:0.027 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site