lkml.org 
[lkml]   [2012]   [Mar]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 1/1] CLONE_PARENT shouldn't allow to set ->exit_signal
The child must not control its ->exit_signal, it is the parent who
decides which signal the child should use for notification.

This means that CLONE_PARENT should not use "clone_flags & CSIGNAL",
the forking task is the sibling of the new process and their parent
doesn't control exit_signal in this case.

This patch uses ->exit_signal of the forking process, but perhaps
we should simply use SIGCHLD.

We read group_leader->exit_signal lockless, this can race with the
ORIGINAL_SIGNAL -> SIGCHLD transition, but this is fine.

Potentially this change allows to kill self_exec_id/parent_exec_id.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
kernel/fork.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index b77fd55..34d7ed1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1310,7 +1310,13 @@ static struct task_struct *copy_process(unsigned long clone_flags,
clear_all_latency_tracing(p);

/* ok, now we should be set up.. */
- p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
+ if (clone_flags & CLONE_THREAD)
+ p->exit_signal = -1;
+ else if (clone_flags & CLONE_PARENT)
+ p->exit_signal = current->group_leader->exit_signal;
+ else
+ p->exit_signal = (clone_flags & CSIGNAL);
+
p->pdeath_signal = 0;
p->exit_state = 0;

--
1.5.5.1



\
 
 \ /
  Last update: 2012-03-14 20:59    [from the cache]
©2003-2011 Jasper Spaans