[FIX] Move urp disarming from atomic context on mm_release

Change-Id: Ia8ff37235b5dfe4d43f8d1578459bb4df444468b
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

3 files changed, 24 insertions, 36 deletions

diff --git a/uprobe/swap_uprobes.c b/uprobe/swap_uprobes.c
index c5daf1c0..f7573d4d 100644
--- a/uprobe/swap_uprobes.c
+++ b/uprobe/swap_uprobes.c
@@ -894,37 +894,6 @@ int swap_register_uretprobe(struct uretprobe *rp)
 EXPORT_SYMBOL_GPL(swap_register_uretprobe);
 
 /**
- * @brief Disarms uretprobes for specified task.
- *
- * @param task Pointer to the task_struct.
- * @return Void.
- */
-void swap_discard_pending_uretprobes(struct task_struct *task)
-{
-	unsigned long flags;
-	struct uretprobe_instance *ri;
-	struct hlist_head *head;
-	struct hlist_node *tmp;
-	DECLARE_NODE_PTR_FOR_HLIST(node);
-
-	spin_lock_irqsave(&uretprobe_lock, flags);
-
-	head = uretprobe_inst_table_head(task->mm);
-	swap_hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
-		if (ri->task == task) {
-			printk(KERN_INFO "%s (%d/%d): pending urp inst: %08lx\n",
-			       task->comm, task->tgid, task->pid,
-			       (unsigned long)ri->rp->up.kp.addr);
-			arch_disarm_urp_inst(ri, task, 0);
-			recycle_urp_inst(ri);
-		}
-	}
-
-	spin_unlock_irqrestore(&uretprobe_lock, flags);
-}
-EXPORT_SYMBOL_GPL(swap_discard_pending_uretprobes);
-
-/**
  * @brief Unregisters uretprobe.
  *
  * @param rp Pointer to the ureprobe.
@@ -1050,7 +1019,7 @@ static void urinst_info_disarm(struct urinst_info *urinst, struct task_struct *t
 	arch_disarm_urp_inst(&ri, task, tramp);
 }
 
-void urinst_info_get_current_hlist(struct hlist_head *head)
+void urinst_info_get_current_hlist(struct hlist_head *head, bool recycle)
 {
 	unsigned long flags;
 	struct task_struct *task = current;
@@ -1076,6 +1045,8 @@ void urinst_info_get_current_hlist(struct hlist_head *head)
 				last = &urinst->hlist;
 			}
 
+			if (recycle)
+				recycle_urp_inst(ri);
 		}
 	}
 	spin_unlock_irqrestore(&uretprobe_lock, flags);
diff --git a/uprobe/swap_uprobes.h b/uprobe/swap_uprobes.h
index cbee7068..66f165ff 100644
--- a/uprobe/swap_uprobes.h
+++ b/uprobe/swap_uprobes.h
@@ -72,7 +72,7 @@ void uinst_info_destroy(struct uinst_info *uinst);
 void uinst_info_disarm(struct uinst_info *uinst, struct task_struct *task);
 
 
-void urinst_info_get_current_hlist(struct hlist_head *head);
+void urinst_info_get_current_hlist(struct hlist_head *head, bool recycle);
 void urinst_info_put_current_hlist(struct hlist_head *head,
 				  struct task_struct *task);
 
@@ -167,7 +167,6 @@ void swap_unregister_uretprobe(struct uretprobe *rp);
 void __swap_unregister_uretprobe(struct uretprobe *rp, int disarm);
 
 void swap_unregister_all_uprobes(struct task_struct *task);
-void swap_discard_pending_uretprobes(struct task_struct *task);
 
 void swap_ujprobe_return(void);
 struct kprobe *get_ukprobe(void *addr, pid_t tgid);
diff --git a/us_manager/helper.c b/us_manager/helper.c
index 2e71afdf..e5eeb2cb 100644
--- a/us_manager/helper.c
+++ b/us_manager/helper.c
@@ -265,7 +265,7 @@ static void rm_uprobes_child(struct kretprobe_instance *ri,
 	proc = sspt_proc_get_by_task(current);
 	if (proc) {
 		sspt_proc_on_each_ip(proc, func_uinst_creare, (void *)&cdata.head);
-		urinst_info_get_current_hlist(&cdata.rhead);
+		urinst_info_get_current_hlist(&cdata.rhead, false);
 	}
 	sspt_proc_write_unlock();
 
@@ -390,9 +390,27 @@ static unsigned long mr_cb(void *data)
 	struct task_struct *task = *(struct task_struct **)data;
 
 	if (task->tgid != task->pid) {
+		struct sspt_proc *proc;
+		struct hlist_head head = HLIST_HEAD_INIT;
+
+		if (task != current) {
+			pr_err("call mm_release in isn't current context\n");
+			return 0;
+		}
+
 		/* if the thread is killed we need to discard pending
 		 * uretprobe instances which have not triggered yet */
-		swap_discard_pending_uretprobes(task);
+		sspt_proc_write_lock();
+		proc = sspt_proc_get_by_task(task);
+		if (proc) {
+			urinst_info_get_current_hlist(&head, true);
+		}
+		sspt_proc_write_unlock();
+
+		if (proc) {
+			/* disarm urp for task */
+			urinst_info_put_current_hlist(&head, task);
+		}
 	} else {
 		call_mm_release(task);
 	}