LDOMS DOMAIN SERVICES UPDATE 5

Orabug: 24601099

Signed-off-by: Aaron Young <aaron.young@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>

diff --git a/drivers/char/vlds.c b/drivers/char/vlds.c
index cf0814767bfd01a8b1e6e3117e1818ffa17c657c..5c95f094b98a6a6e8ec59576d8871309771d2d4d 100644 (file)
--- a/drivers/char/vlds.c
+++ b/drivers/char/vlds.c
@@ -294,6 +294,7 @@ static int vlds_signal_event(pid_t tgid, int fd)
        struct file *efd_file;
        struct eventfd_ctx *efd_ctx;
        struct task_struct *utask;
+       struct pid *pid;
 
        /*
         * Signal the process that there is an event pending
@@ -304,8 +305,15 @@ static int vlds_signal_event(pid_t tgid, int fd)
 
        rcu_read_lock();
 
+       /* Get the pid */
+       pid = find_vpid(tgid);
+       if (pid == NULL) {
+               rcu_read_unlock();
+               return -ESRCH;
+       }
+
        /* Get the task struct */
-       utask = pid_task(find_vpid(tgid), PIDTYPE_PID);
+       utask = pid_task(pid, PIDTYPE_PID);
        if (!utask || !utask->files) {
                rcu_read_unlock();
                return -EIO;
@@ -340,12 +348,13 @@ static int vlds_signal_event(pid_t tgid, int fd)
 static void vlds_add_event_all(struct vlds_dev *vlds, u64 type)
 {
        struct vlds_event_info *event_info;
+       struct vlds_event_info *nxt;
        struct vlds_event *event;
        int rv;
 
        mutex_lock(&vlds_event_info_list_mutex);
 
-       list_for_each_entry(event_info, &vlds_event_info_list, list) {
+       list_for_each_entry_safe(event_info, nxt, &vlds_event_info_list, list) {
 
                event = kzalloc(sizeof(struct vlds_event), GFP_KERNEL);
                if (unlikely(event == NULL)) {
@@ -362,14 +371,29 @@ static void vlds_add_event_all(struct vlds_dev *vlds, u64 type)
                        /* just give an error if we failed to add the event */
                        pr_err("%s: Failed to create %llu event for tgid=%u\n",
                            vlds->int_name, type, event_info->tgid);
+
+                       /*
+                        * If the event failed to signal because the
+                        * process no longer exists, we will prune the
+                        * stale event_info from the list. This can happen
+                        * if a process registers an eventfd but fails to
+                        * unregister it before exiting.
+                        */
+                       if (rv == -ESRCH) {
+                               pr_err("%s: Removing stale event_info for "
+                                      "tgid=%u\n", vlds->int_name,
+                                      event_info->tgid);
+                               vlds_remove_event_info(event_info->tgid);
+                       }
                }
        }
 
        mutex_unlock(&vlds_event_info_list_mutex);
 }
 
-static int vlds_add_svc_event(pid_t tgid, struct vlds_service_info *svc_info,
-       u64 type, vlds_ver_t *neg_vers)
+static void vlds_add_svc_event(struct vlds_dev *vlds, pid_t tgid,
+                              struct vlds_service_info *svc_info, u64 type,
+                              vlds_ver_t *neg_vers)
 {
        struct vlds_event_info *event_info;
        struct vlds_event *event;
@@ -386,7 +410,7 @@ static int vlds_add_svc_event(pid_t tgid, struct vlds_service_info *svc_info,
                 * of using polling - which is valid.
                 */
                mutex_unlock(&vlds_event_info_list_mutex);
-               return 0;
+               return;
        }
 
        event = kzalloc(sizeof(struct vlds_event), GFP_KERNEL);
@@ -395,7 +419,7 @@ static int vlds_add_svc_event(pid_t tgid, struct vlds_service_info *svc_info,
                        dprintk("failed to allocate event for "
                            "service %llx\n", svc_info->handle);
                mutex_unlock(&vlds_event_info_list_mutex);
-               return -ENOMEM;
+               return;
        }
 
        event->type = type;
@@ -407,10 +431,26 @@ static int vlds_add_svc_event(pid_t tgid, struct vlds_service_info *svc_info,
            &event_info->event_list);
 
        rv = vlds_signal_event(tgid, event_info->fd);
+       if (rv) {
+               /* just give an error if we failed to add the event */
+               pr_err("%s: Failed to create event (type = %llu) for tgid=%u\n",
+                   vlds->int_name, type, tgid);
 
-       mutex_unlock(&vlds_event_info_list_mutex);
+               /*
+                * If the event failed to signal because the
+                * process no longer exists, we will prune the
+                * stale event_info from the list. This can happen
+                * if a process registers an eventfd but fails to
+                * unregister it before exiting.
+                */
+               if (rv == -ESRCH) {
+                       pr_err("%s: Removing stale event_info for "
+                              "tgid=%u\n", vlds->int_name, tgid);
+                       vlds_remove_event_info(tgid);
+               }
+       }
 
-       return rv;
+       mutex_unlock(&vlds_event_info_list_mutex);
 
 }
 
@@ -419,7 +459,6 @@ static void vlds_add_event_svc_all(struct vlds_dev *vlds,
        struct vlds_service_info *svc_info, u64 type, vlds_ver_t *neg_vers)
 {
        struct vlds_tgid_info *tgid_info;
-       int rv;
 
        list_for_each_entry(tgid_info, &svc_info->tgid_list, list) {
 
@@ -427,13 +466,8 @@ static void vlds_add_event_svc_all(struct vlds_dev *vlds,
                if (!tgid_info->event_reg)
                        continue;
 
-               rv = vlds_add_svc_event(tgid_info->tgid, svc_info,
+               vlds_add_svc_event(vlds, tgid_info->tgid, svc_info,
                    type, neg_vers);
-               if (rv) {
-                       /* just give an error if we failed to add the event */
-                       pr_err("%s: Failed to create event (type = %llu)\n",
-                           vlds->int_name, type);
-               }
        }
 }
 
@@ -1012,16 +1046,9 @@ static int vlds_svc_reg(struct vlds_dev *vlds, const void __user *uarg)
                 * event for the process - since it will probably expect one.
                 */
                if (is_event_reg &&
-                   svc_info->state == VLDS_HDL_STATE_CONNECTED) {
-                       rv = vlds_add_svc_event(tgid, svc_info,
+                   svc_info->state == VLDS_HDL_STATE_CONNECTED)
+                       vlds_add_svc_event(vlds, tgid, svc_info,
                            VLDS_EVENT_TYPE_REG, &svc_info->neg_vers);
-                       if (rv) {
-                               /* just give an error if add event fails */
-                               pr_err("%s: Failed to create registration "
-                                   "event (%llx)\n", vlds->int_name,
-                                   svc_info->handle);
-                       }
-               }
 
                dprintk("%s: registered tgid %u with service %s (client = %u) "
                    "(hdl = %llx)\n", vlds->int_name, tgid, svc_str,