Author: Eric W. Biederman <[EMAIL PROTECTED]>

Implement the basic helper function that walks all of the processes in a
pid namespace and sends them all a signal.

Both locations that could use this functions are also updated to use this
function.

I use find_ge_pid instead of for_each_process because it has a chance of
not touching every process in the system.

[EMAIL PROTECTED]: Optimize away nr <= 1 check, against latest Linus tree]
Signed-off-by: Eric W. Biederman <[EMAIL PROTECTED]>
Signed-off-by: Daniel Hokka Zakrisson <[EMAIL PROTECTED]>

diff --git a/include/linux/sched.h b/include/linux/sched.h
index ba2f859..83597f8 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1778,6 +1778,8 @@ extern void release_task(struct task_struct * p);
 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
extern int force_sigsegv(int, struct task_struct *);
 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
+extern int __kill_pid_ns_info(int sig, struct siginfo *info, struct
pid_namespace *ns);
+extern int kill_pid_ns_info(int sig, struct siginfo *info, struct
pid_namespace *ns);
 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid
*pgrp);
 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *,
uid_t, uid_t, u32);
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 98702b4..9226423 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -153,29 +153,14 @@ void free_pid_ns(struct kref *kref)

 void zap_pid_ns_processes(struct pid_namespace *pid_ns)
 {
-       int nr;
        int rc;

        /*
         * The last thread in the cgroup-init thread group is terminating. *
Find remaining pid_ts in the namespace, signal and wait for them * to
exit.
-        *
-        * Note:  This signals each threads in the namespace - even those that
-        *        belong to the same thread group, To avoid this, we would have 
-        *
          to walk the entire tasklist looking a processes in this
-        *        namespace, but that could be unnecessarily expensive if the - 
 *      
 pid namespace has just a few processes. Or we need to
-        *        maintain a tasklist for each pid namespace.
-        *
         */
-       read_lock(&tasklist_lock);
-       nr = next_pidmap(pid_ns, 1);
-       while (nr > 0) {
-               kill_proc_info(SIGKILL, SEND_SIG_PRIV, nr);
-               nr = next_pidmap(pid_ns, nr);
-       }
-       read_unlock(&tasklist_lock);
+       kill_pid_ns_info(SIGKILL, SEND_SIG_PRIV, pid_ns);

        do {
                clear_thread_flag(TIF_SIGPENDING);
diff --git a/kernel/signal.c b/kernel/signal.c
index 6c0958e..fc42428 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1118,6 +1118,45 @@ out_unlock:
 }
 EXPORT_SYMBOL_GPL(kill_pid_info_as_uid);

+int __kill_pid_ns_info(int sig, struct siginfo *info, struct
pid_namespace *ns)
+{
+       int retval = 0, count = 0;
+       struct task_struct *p;
+       struct pid *pid;
+       int nr;
+
+       /* Since there isn't a pid namespace list of tasks use the closest +    
 *
approximation we have: find_ge_pid.
+        */
+       nr = 1;
+       while ((pid = find_ge_pid(nr + 1, ns))) {
+               int err;
+
+               nr = pid_nr_ns(pid, ns);
+               p = pid_task(pid, PIDTYPE_PID);
+               if (!p || (nr <= 1) || !thread_group_leader(p) ||
+                   same_thread_group(p, current))
+                       continue;
+
+               err = group_send_sig_info(sig, info, p);
+               ++count;
+               if (err != -EPERM)
+                       retval = err;
+       }
+       return count ? retval : -ESRCH;
+}
+
+int kill_pid_ns_info(int sig, struct siginfo *info, struct pid_namespace
*ns)
+{
+       int retval;
+
+       read_lock(&tasklist_lock);
+       retval = __kill_pid_ns_info(sig, info, ns);
+       read_unlock(&tasklist_lock);
+
+       return retval;
+}
+
 /*
  * kill_something_info() interprets pid in interesting ways just like
kill(2).
  *
@@ -1141,18 +1180,7 @@ static int kill_something_info(int sig, struct
siginfo *info, int pid)
                ret = __kill_pgrp_info(sig, info,
                                pid ? find_vpid(-pid) : task_pgrp(current));
        } else {
-               int retval = 0, count = 0;
-               struct task_struct * p;
-
-               for_each_process(p) {
-                       if (p->pid > 1 && !same_thread_group(p, current)) {
-                               int err = group_send_sig_info(sig, info, p);
-                               ++count;
-                               if (err != -EPERM)
-                                       retval = err;
-                       }
-               }
-               ret = count ? retval : -ESRCH;
+               ret = __kill_pid_ns_info(sig, info, 
task_active_pid_ns(current));
        }
        read_unlock(&tasklist_lock);

-- 
1.5.5.1


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