exit_notify: fix kill_orphaned_pgrp() usage with mt exit

[sfrench/cifs-2.6.git] / kernel / exit.c

diff --git a/kernel/exit.c b/kernel/exit.c
index 506a957b665a69bbf84794e233b8032f2d98b280..cd20bf07e9e3b7bb2260c4a5939642c9e4bcb0a5 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -214,20 +214,19 @@ struct pid *session_of_pgrp(struct pid *pgrp)
 static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task)
 {
        struct task_struct *p;
-       int ret = 1;
 
        do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
-               if (p == ignored_task
-                               || p->exit_state
-                               || is_global_init(p->real_parent))
+               if ((p == ignored_task) ||
+                   (p->exit_state && thread_group_empty(p)) ||
+                   is_global_init(p->real_parent))
                        continue;
+
                if (task_pgrp(p->real_parent) != pgrp &&
-                   task_session(p->real_parent) == task_session(p)) {
-                       ret = 0;
-                       break;
-               }
+                   task_session(p->real_parent) == task_session(p))
+                       return 0;
        } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
-       return ret;     /* (sighing) "Often!" */
+
+       return 1;
 }
 
 int is_current_pgrp_orphaned(void)
@@ -255,6 +254,37 @@ static int has_stopped_jobs(struct pid *pgrp)
        return retval;
 }
 
+/*
+ * Check to see if any process groups have become orphaned as
+ * a result of our exiting, and if they have any stopped jobs,
+ * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
+ */
+static void
+kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
+{
+       struct pid *pgrp = task_pgrp(tsk);
+       struct task_struct *ignored_task = tsk;
+
+       if (!parent)
+                /* exit: our father is in a different pgrp than
+                 * we are and we were the only connection outside.
+                 */
+               parent = tsk->real_parent;
+       else
+               /* reparent: our child is in a different pgrp than
+                * we are, and it was the only connection outside.
+                */
+               ignored_task = NULL;
+
+       if (task_pgrp(parent) != pgrp &&
+           task_session(parent) == task_session(tsk) &&
+           will_become_orphaned_pgrp(pgrp, ignored_task) &&
+           has_stopped_jobs(pgrp)) {
+               __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
+               __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
+       }
+}
+
 /**
  * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
  *
@@ -635,22 +665,7 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
            p->exit_signal != -1 && thread_group_empty(p))
                do_notify_parent(p, p->exit_signal);
 
-       /*
-        * process group orphan check
-        * Case ii: Our child is in a different pgrp
-        * than we are, and it was the only connection
-        * outside, so the child pgrp is now orphaned.
-        */
-       if ((task_pgrp(p) != task_pgrp(father)) &&
-           (task_session(p) == task_session(father))) {
-               struct pid *pgrp = task_pgrp(p);
-
-               if (will_become_orphaned_pgrp(pgrp, NULL) &&
-                   has_stopped_jobs(pgrp)) {
-                       __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
-                       __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
-               }
-       }
+       kill_orphaned_pgrp(p, father);
 }
 
 /*
@@ -735,11 +750,9 @@ static void forget_original_parent(struct task_struct *father)
  * Send signals to all our closest relatives so that they know
  * to properly mourn us..
  */
-static void exit_notify(struct task_struct *tsk)
+static void exit_notify(struct task_struct *tsk, int group_dead)
 {
        int state;
-       struct task_struct *t;
-       struct pid *pgrp;
 
        /*
         * This does two things:
@@ -753,25 +766,8 @@ static void exit_notify(struct task_struct *tsk)
        exit_task_namespaces(tsk);
 
        write_lock_irq(&tasklist_lock);
-       /*
-        * Check to see if any process groups have become orphaned
-        * as a result of our exiting, and if they have any stopped
-        * jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
-        *
-        * Case i: Our father is in a different pgrp than we are
-        * and we were the only connection outside, so our pgrp
-        * is about to become orphaned.
-        */
-       t = tsk->real_parent;
-
-       pgrp = task_pgrp(tsk);
-       if ((task_pgrp(t) != pgrp) &&
-           (task_session(t) == task_session(tsk)) &&
-           will_become_orphaned_pgrp(pgrp, tsk) &&
-           has_stopped_jobs(pgrp)) {
-               __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
-               __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
-       }
+       if (group_dead)
+               kill_orphaned_pgrp(tsk->group_leader, NULL);
 
        /* Let father know we died
         *
@@ -788,8 +784,8 @@ static void exit_notify(struct task_struct *tsk)
         * the same after a fork.
         */
        if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 &&
-           ( tsk->parent_exec_id != t->self_exec_id  ||
-             tsk->self_exec_id != tsk->parent_exec_id)
+           (tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
+            tsk->self_exec_id != tsk->parent_exec_id)
            && !capable(CAP_KILL))
                tsk->exit_signal = SIGCHLD;
 
@@ -986,7 +982,7 @@ NORET_TYPE void do_exit(long code)
                module_put(tsk->binfmt->module);
 
        proc_exit_connector(tsk);
-       exit_notify(tsk);
+       exit_notify(tsk, group_dead);
 #ifdef CONFIG_NUMA
        mpol_free(tsk->mempolicy);
        tsk->mempolicy = NULL;