[FIX] sspt_filter handling

- Add rwlock to avoid race conditions (i.e. img copied to sspt
  multiple times)
- Use GFP_ATOMIC for sspt_filter allocation (done in atomic context)

Change-Id: I0809a8eb16555e2882d900cab8c544a32bdc16b1
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

4 files changed, 22 insertions, 8 deletions

diff --git a/us_manager/pf/pf_group.c b/us_manager/pf/pf_group.c
index fb92fdb5..548fbe06 100644
--- a/us_manager/pf/pf_group.c
+++ b/us_manager/pf/pf_group.c
@@ -490,11 +490,15 @@ static enum pf_inst_flag pfg_check_task(struct task_struct *task)
 			flag = PIF_FIRST;
 		}
 
-		if (proc && sspt_proc_is_filter_new(proc, pfg)) {
-			img_proc_copy_to_sspt(pfg->i_proc, proc);
-			sspt_proc_add_filter(proc, pfg);
-			pfg_add_proc(pfg, proc);
-			flag = flag == PIF_FIRST ? flag : PIF_ADD_PFG;
+		if (proc) {
+			write_lock(&proc->filter_lock);
+				if (sspt_proc_is_filter_new(proc, pfg)) {
+					img_proc_copy_to_sspt(pfg->i_proc, proc);
+					sspt_proc_add_filter(proc, pfg);
+					pfg_add_proc(pfg, proc);
+					flag = flag == PIF_FIRST ? flag : PIF_ADD_PFG;
+			}
+			write_unlock(&proc->filter_lock);
 		}
 	}
 	read_unlock(&pfg_list_lock);
diff --git a/us_manager/sspt/sspt_filter.c b/us_manager/sspt/sspt_filter.c
index 0d02e73c..2925d7f6 100644
--- a/us_manager/sspt/sspt_filter.c
+++ b/us_manager/sspt/sspt_filter.c
@@ -10,12 +10,11 @@ struct sspt_filter *sspt_filter_create(struct sspt_proc *proc,
 {
 	struct sspt_filter *fl;
 
-	fl = kmalloc(sizeof(*fl), GFP_KERNEL);
+	fl = kmalloc(sizeof(*fl), GFP_ATOMIC);
 	if (fl == NULL)
 		return NULL;
 
 	INIT_LIST_HEAD(&fl->list);
-	list_add(&fl->list, &proc->filter_list);
 
 	fl->proc = proc;
 	fl->pfg = pfg;
diff --git a/us_manager/sspt/sspt_proc.c b/us_manager/sspt/sspt_proc.c
index d9473a8b..fae2e3f1 100644
--- a/us_manager/sspt/sspt_proc.c
+++ b/us_manager/sspt/sspt_proc.c
@@ -107,6 +107,7 @@ struct sspt_proc *sspt_proc_create(struct task_struct *task)
 		proc->task = task->group_leader;
 		proc->sm = create_sm_us(task);
 		INIT_LIST_HEAD(&proc->file_list);
+		rwlock_init(&proc->filter_lock);
 		INIT_LIST_HEAD(&proc->filter_list);
 		atomic_set(&proc->usage, 1);
 
@@ -459,7 +460,11 @@ void sspt_proc_insert_files(struct sspt_proc *proc, struct list_head *head)
  */
 void sspt_proc_add_filter(struct sspt_proc *proc, struct pf_group *pfg)
 {
-	sspt_filter_create(proc, pfg);
+	struct sspt_filter *f;
+
+	f = sspt_filter_create(proc, pfg);
+	if (f)
+		list_add(&f->list, &proc->filter_list);
 }
 
 /**
@@ -473,12 +478,14 @@ void sspt_proc_del_filter(struct sspt_proc *proc, struct pf_group *pfg)
 {
 	struct sspt_filter *fl, *tmp;
 
+	write_lock(&proc->filter_lock);
 	list_for_each_entry_safe(fl, tmp, &proc->filter_list, list) {
 		if (fl->pfg == pfg) {
 			list_del(&fl->list);
 			sspt_filter_free(fl);
 		}
 	}
+	write_unlock(&proc->filter_lock);
 }
 
 /**
@@ -491,10 +498,12 @@ void sspt_proc_del_all_filters(struct sspt_proc *proc)
 {
 	struct sspt_filter *fl, *tmp;
 
+	write_lock(&proc->filter_lock);
 	list_for_each_entry_safe(fl, tmp, &proc->filter_list, list) {
 		list_del(&fl->list);
 		sspt_filter_free(fl);
 	}
+	write_unlock(&proc->filter_lock);
 }
 
 /**
@@ -546,6 +555,7 @@ bool sspt_proc_is_send_event(struct sspt_proc *proc)
 {
 	bool is_send = false;
 
+	/* FIXME: add read lock (deadlock in sampler) */
 	sspt_proc_on_each_filter(proc, is_send_event, (void *)&is_send);
 
 	return is_send;
diff --git a/us_manager/sspt/sspt_proc.h b/us_manager/sspt/sspt_proc.h
index 46b9e44e..03a1db1d 100644
--- a/us_manager/sspt/sspt_proc.h
+++ b/us_manager/sspt/sspt_proc.h
@@ -53,6 +53,7 @@ struct sspt_proc {
 	unsigned long r_state_addr;	/**< address of r_state */
 	struct slot_manager *sm;	/**< Ptr to the manager slot */
 	struct list_head file_list;	/**< For sspt_file */
+	rwlock_t filter_lock;
 	struct list_head filter_list;	/**< Filter list */
 	unsigned first_install:1;	/**< Install flag */
 	struct sspt_feature *feature;	/**< Ptr to the feature */