sys_setsid() still deals with pid_t's from the global namespace. This means
that the "session > 1" check can't help for sub-namespace init, setsid() can't
succeed because copy_process(CLONE_NEWPID) populates PIDTYPE_PGID/SID links.
Remove the usage of task_struct->pid and convert the code to use "struct pid".
This also simplifies and speedups the code, saves one find_pid().
Signed-off-by: Oleg Nesterov <[EMAIL PROTECTED]>
--- PT/kernel/sys.c~1_setsid 2007-11-26 15:52:15.000000000 +0300
+++ PT/kernel/sys.c 2007-11-26 16:10:43.000000000 +0300
@@ -1045,35 +1045,33 @@ asmlinkage long sys_getsid(pid_t pid)
asmlinkage long sys_setsid(void)
{
struct task_struct *group_leader = current->group_leader;
- pid_t session;
+ struct pid *sid = task_pid(group_leader);
+ pid_t session = pid_vnr(sid);
int err = -EPERM;
write_lock_irq(&tasklist_lock);
-
/* Fail if I am already a session leader */
if (group_leader->signal->leader)
goto out;
- session = group_leader->pid;
- /* Fail if a process group id already exists that equals the
- * proposed session id.
+ /* Fail if a process group id already exists that equals the proposed
+ * session id.
*
- * Don't check if session id == 1 because kernel threads use this
- * session id and so the check will always fail and make it so
- * init cannot successfully call setsid.
+ * Don't check if session == 1 because kernel threads and CLONE_NEWPID
+ * tasks use this session id and so the check will always fail and make
+ * it so init cannot successfully call setsid.
*/
- if (session > 1 && find_task_by_pid_type_ns(PIDTYPE_PGID,
- session, &init_pid_ns))
+ if (session != 1 && pid_task(sid, PIDTYPE_PGID))
goto out;
group_leader->signal->leader = 1;
- __set_special_pids(session, session);
+ __set_special_pids(pid_nr(sid), pid_nr(sid));
spin_lock(&group_leader->sighand->siglock);
group_leader->signal->tty = NULL;
spin_unlock(&group_leader->sighand->siglock);
- err = task_pgrp_vnr(group_leader);
+ err = session;
out:
write_unlock_irq(&tasklist_lock);
return err;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
