[IMPROVE] remove atomic context for pfg_list

Change-Id: I8200310bfe892fc712a0d5679a35464b9de5fee5
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

diff --git a/us_manager/pf/pf_group.c b/us_manager/pf/pf_group.c
index bfe86fe..16fee13 100644 (file)
--- a/us_manager/pf/pf_group.c
+++ b/us_manager/pf/pf_group.c
@@ -57,8 +57,30 @@ struct pl_struct {
        struct sspt_proc *proc;
 };
 
+
 static LIST_HEAD(pfg_list);
-static DEFINE_RWLOCK(pfg_list_lock);
+static DECLARE_RWSEM(pfg_list_sem);
+
+static void pfg_list_rlock(void)
+{
+       down_read(&pfg_list_sem);
+}
+
+static void pfg_list_runlock(void)
+{
+       up_read(&pfg_list_sem);
+}
+
+static void pfg_list_wlock(void)
+{
+       down_write(&pfg_list_sem);
+}
+
+static void pfg_list_wunlock(void)
+{
+       up_write(&pfg_list_sem);
+}
+
 
 /* struct pl_struct */
 static struct pl_struct *create_pl_struct(struct sspt_proc *proc)
@@ -258,7 +280,7 @@ struct pf_group *get_pf_group_by_dentry(struct dentry *dentry, void *priv)
 {
        struct pf_group *pfg;
 
-       write_lock(&pfg_list_lock);
+       pfg_list_wlock();
        list_for_each_entry(pfg, &pfg_list, list) {
                if (check_pf_by_dentry(&pfg->filter, dentry)) {
                        atomic_inc(&pfg->usage);
@@ -275,7 +297,7 @@ struct pf_group *get_pf_group_by_dentry(struct dentry *dentry, void *priv)
        pfg_add_to_list(pfg);
 
 unlock:
-       write_unlock(&pfg_list_lock);
+       pfg_list_wunlock();
        return pfg;
 }
 EXPORT_SYMBOL_GPL(get_pf_group_by_dentry);
@@ -291,7 +313,7 @@ struct pf_group *get_pf_group_by_tgid(pid_t tgid, void *priv)
 {
        struct pf_group *pfg;
 
-       write_lock(&pfg_list_lock);
+       pfg_list_wlock();
        list_for_each_entry(pfg, &pfg_list, list) {
                if (check_pf_by_tgid(&pfg->filter, tgid)) {
                        atomic_inc(&pfg->usage);
@@ -308,7 +330,7 @@ struct pf_group *get_pf_group_by_tgid(pid_t tgid, void *priv)
        pfg_add_to_list(pfg);
 
 unlock:
-       write_unlock(&pfg_list_lock);
+       pfg_list_wunlock();
        return pfg;
 }
 EXPORT_SYMBOL_GPL(get_pf_group_by_tgid);
@@ -325,7 +347,7 @@ struct pf_group *get_pf_group_by_comm(char *comm, void *priv)
        int ret;
        struct pf_group *pfg;
 
-       write_lock(&pfg_list_lock);
+       pfg_list_wlock();
        list_for_each_entry(pfg, &pfg_list, list) {
                if (check_pf_by_comm(&pfg->filter, comm)) {
                        atomic_inc(&pfg->usage);
@@ -347,7 +369,7 @@ struct pf_group *get_pf_group_by_comm(char *comm, void *priv)
 
        pfg_add_to_list(pfg);
 unlock:
-       write_unlock(&pfg_list_lock);
+       pfg_list_wunlock();
        return pfg;
 }
 EXPORT_SYMBOL_GPL(get_pf_group_by_comm);
@@ -362,7 +384,7 @@ struct pf_group *get_pf_group_dumb(void *priv)
 {
        struct pf_group *pfg;
 
-       write_lock(&pfg_list_lock);
+       pfg_list_wlock();
        list_for_each_entry(pfg, &pfg_list, list) {
                if (check_pf_dumb(&pfg->filter)) {
                        atomic_inc(&pfg->usage);
@@ -379,7 +401,7 @@ struct pf_group *get_pf_group_dumb(void *priv)
        pfg_add_to_list(pfg);
 
 unlock:
-       write_unlock(&pfg_list_lock);
+       pfg_list_wunlock();
        return pfg;
 }
 EXPORT_SYMBOL_GPL(get_pf_group_dumb);
@@ -393,9 +415,9 @@ EXPORT_SYMBOL_GPL(get_pf_group_dumb);
 void put_pf_group(struct pf_group *pfg)
 {
        if (atomic_dec_and_test(&pfg->usage)) {
-               write_lock(&pfg_list_lock);
+               pfg_list_wlock();
                pfg_del_from_list(pfg);
-               write_unlock(&pfg_list_lock);
+               pfg_list_wunlock();
 
                pfg_free(pfg);
        }
@@ -438,7 +460,7 @@ static int check_task_on_filters(struct task_struct *task)
        int ret = 0;
        struct pf_group *pfg;
 
-       read_lock(&pfg_list_lock);
+       pfg_list_rlock();
        list_for_each_entry(pfg, &pfg_list, list) {
                if (check_task_f(&pfg->filter, task)) {
                        ret = 1;
@@ -447,7 +469,7 @@ static int check_task_on_filters(struct task_struct *task)
        }
 
 unlock:
-       read_unlock(&pfg_list_lock);
+       pfg_list_runlock();
        return ret;
 }
 
@@ -464,7 +486,7 @@ static enum pf_inst_flag pfg_check_task(struct task_struct *task)
        struct sspt_proc *proc = NULL;
        enum pf_inst_flag flag = PIF_NONE;
 
-       read_lock(&pfg_list_lock);
+       pfg_list_rlock();
        list_for_each_entry(pfg, &pfg_list, list) {
                if (check_task_f(&pfg->filter, task) == NULL)
                        continue;
@@ -494,7 +516,7 @@ static enum pf_inst_flag pfg_check_task(struct task_struct *task)
                        write_unlock(&proc->filter_lock);
                }
        }
-       read_unlock(&pfg_list_lock);
+       pfg_list_runlock();
 
        return flag;
 }
@@ -605,8 +627,22 @@ void uninstall_page(unsigned long addr)
 }
 
 
-static struct task_struct *get_untracked_task(void)
+static void install_cb(void *unused)
+{
+       check_task_and_install(current);
+}
+
+
+
+
+struct task_item {
+       struct list_head list;
+       struct task_struct *task;
+};
+
+static void tasks_get(struct list_head *head)
 {
+       struct task_item *item;
        struct task_struct *task;
 
        rcu_read_lock();
@@ -617,22 +653,53 @@ static struct task_struct *get_untracked_task(void)
                if (sspt_proc_get_by_task(task))
                        continue;
 
-               if (check_task_on_filters(task)) {
-                       get_task_struct(task);
+               /* TODO: get rid of GFP_ATOMIC */
+               item = kmalloc(sizeof(*item), GFP_ATOMIC);
+               if (item == NULL) {
+                       WARN(1, "out of memory\n");
                        goto unlock;
                }
-       }
 
-       task = NULL;
+               get_task_struct(task);
+               item->task = task;
+               list_add(&item->list, head);
+       }
 
 unlock:
        rcu_read_unlock();
-       return task;
 }
 
-static void install_cb(void *unused)
+static void tasks_install_and_put(struct list_head *head)
 {
-       check_task_and_install(current);
+       struct task_item *item, *n;
+
+       list_for_each_entry_safe(item, n, head, list) {
+               int ret;
+               struct task_struct *task;
+
+               task = item->task;
+               if (!check_task_on_filters(task))
+                       goto put_task;
+
+               ret = taskctx_run(task, install_cb, NULL);
+               if (ret) {
+                       pr_err("cannot tracking task[%u %u %s] ret=%d\n",
+                              task->tgid, task->pid, task->comm, ret);
+               }
+
+put_task:
+               put_task_struct(task);
+               list_del(&item->list);
+               kfree(item);
+       }
+}
+
+static void do_install_all(void)
+{
+       LIST_HEAD(head);
+
+       tasks_get(&head);
+       tasks_install_and_put(&head);
 }
 
 /**
@@ -643,32 +710,14 @@ static void install_cb(void *unused)
 void install_all(void)
 {
        int ret;
-       struct task_struct *task, *first;
-
-       first = get_untracked_task();
-       if (first == NULL)
-               return;
-
 
        ret = taskctx_get();
-       if (ret) {
-               put_task_struct(first);
-
-               pr_err("taskctx_get ret=%d\n", ret);;
-               return;
-       }
-
-       for (task = first; task; task = get_untracked_task()) {
-               ret = taskctx_run(task, install_cb, NULL);
-               if (ret) {
-                       pr_err("cannot tracking task[%u %u %s] ret=%d\n",
-                              task->tgid, task->pid, task->comm, ret);
-               }
-
-               put_task_struct(task);
+       if (!ret) {
+               do_install_all();
+               taskctx_put();
+       } else {
+               pr_err("taskctx_get ret=%d\n", ret);
        }
-
-       taskctx_put();
 }
 
 /**