[PATCH] setpgid: should work for sub-threads
setsid() does not work unless the calling process is a
thread_group_leader().
'man setpgid' does not tell anything about that, so I consider this
behaviour is a bug.
Signed-off-by: Oren Laadan <orenl@cs.columbia.edu>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/sys.c b/kernel/sys.c
index 43e5572..f497bf5 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1215,24 +1215,22 @@
asmlinkage long sys_setsid(void)
{
+ struct task_struct *group_leader = current->group_leader;
struct pid *pid;
int err = -EPERM;
- if (!thread_group_leader(current))
- return -EINVAL;
-
down(&tty_sem);
write_lock_irq(&tasklist_lock);
- pid = find_pid(PIDTYPE_PGID, current->pid);
+ pid = find_pid(PIDTYPE_PGID, group_leader->pid);
if (pid)
goto out;
- current->signal->leader = 1;
- __set_special_pids(current->pid, current->pid);
- current->signal->tty = NULL;
- current->signal->tty_old_pgrp = 0;
- err = process_group(current);
+ group_leader->signal->leader = 1;
+ __set_special_pids(group_leader->pid, group_leader->pid);
+ group_leader->signal->tty = NULL;
+ group_leader->signal->tty_old_pgrp = 0;
+ err = process_group(group_leader);
out:
write_unlock_irq(&tasklist_lock);
up(&tty_sem);