proc: uid: Changes the thread notifier to profile event notifier.

In order to keep the code consistent with all other platforms, the
thread notifier is changed to profile event notifier.

Change-Id: I5b996c789927b42dacba10af6fe81a21866e2c8f

2 files changed, 19 insertions, 34 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index a946880..0559caa 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -704,7 +704,7 @@ config MPU_SENSORS_MPU6050
 
 config UID_CPUTIME
 	tristate "Per-UID cpu time statistics"
-	default n
+	depends on PROFILING
 	help
 	  Per UID based cpu time statistics exported to /proc/uid_cputime
 
diff --git a/drivers/misc/uid_cputime.c b/drivers/misc/uid_cputime.c
index c032197..87c8ddd 100644
--- a/drivers/misc/uid_cputime.c
+++ b/drivers/misc/uid_cputime.c
@@ -13,8 +13,6 @@
  *
  */
 
-#include <asm/thread_notify.h>
-
 #include <linux/atomic.h>
 #include <linux/err.h>
 #include <linux/hashtable.h>
@@ -22,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/proc_fs.h>
+#include <linux/profile.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
@@ -30,7 +29,7 @@
 #define UID_HASH_BITS	10
 DECLARE_HASHTABLE(hash_table, UID_HASH_BITS);
 
-static DEFINE_SPINLOCK(uid_lock);
+static DEFINE_MUTEX(uid_lock);
 static struct proc_dir_entry *parent;
 
 struct uid_entry {
@@ -82,7 +81,7 @@ static int uid_stat_show(struct seq_file *m, void *v)
 	cputime_t stime;
 	unsigned long bkt;
 
-	spin_lock(&uid_lock);
+	mutex_lock(&uid_lock);
 
 	hash_for_each(hash_table, bkt, node, uid_entry, hash) {
 		uid_entry->active_stime = 0;
@@ -94,7 +93,7 @@ static int uid_stat_show(struct seq_file *m, void *v)
 		uid_entry = find_or_register_uid(task_uid(task));
 		if (!uid_entry) {
 			read_unlock(&tasklist_lock);
-			spin_unlock(&uid_lock);
+			mutex_unlock(&uid_lock);
 			pr_err("%s: failed to find the uid_entry for uid %d\n",
 						__func__, task_uid(task));
 			return -ENOMEM;
@@ -115,7 +114,7 @@ static int uid_stat_show(struct seq_file *m, void *v)
 						cputime_to_usecs(total_stime));
 	}
 
-	spin_unlock(&uid_lock);
+	mutex_unlock(&uid_lock);
 	return 0;
 }
 
@@ -163,7 +162,7 @@ static ssize_t uid_remove_write(struct file *file,
 		return -EINVAL;
 	}
 
-	spin_lock(&uid_lock);
+	mutex_lock(&uid_lock);
 
 	for (; uid_start <= uid_end; uid_start++) {
 		hash_for_each_possible_safe(hash_table, uid_entry, node, tmp,
@@ -173,7 +172,7 @@ static ssize_t uid_remove_write(struct file *file,
 		}
 	}
 
-	spin_unlock(&uid_lock);
+	mutex_unlock(&uid_lock);
 	return count;
 }
 
@@ -183,14 +182,19 @@ static const struct file_operations uid_remove_fops = {
 	.write		= uid_remove_write,
 };
 
-static void uid_task_exit(struct task_struct *task)
+static int process_notifier(struct notifier_block *self,
+			unsigned long cmd, void *v)
 {
+	struct task_struct *task = v;
 	struct uid_entry *uid_entry;
-	uid_t uid = task_uid(task);
 	cputime_t utime, stime;
+	uid_t uid;
 
-	spin_lock(&uid_lock);
+	if (!task)
+		return NOTIFY_OK;
 
+	mutex_lock(&uid_lock);
+	uid = task_uid(task);
 	uid_entry = find_or_register_uid(uid);
 	if (!uid_entry) {
 		pr_err("%s: failed to find uid %d\n", __func__, uid);
@@ -202,27 +206,8 @@ static void uid_task_exit(struct task_struct *task)
 	uid_entry->stime += stime;
 
 exit:
-	spin_unlock(&uid_lock);
-}
-
-static int process_notifier(struct notifier_block *self,
-			unsigned long cmd, void *v)
-{
-	struct thread_info *thread = v;
-	struct task_struct *task = v ? thread->task : NULL;
-
-	if (!task)
-		return NOTIFY_DONE;
-
-	switch (cmd) {
-	case THREAD_NOTIFY_EXIT:
-		uid_task_exit(task);
-		break;
-	default:
-		break;
-	}
-
-	return NOTIFY_DONE;
+	mutex_unlock(&uid_lock);
+	return NOTIFY_OK;
 }
 
 static struct notifier_block process_notifier_block = {
@@ -245,7 +230,7 @@ static int __init proc_uid_cputime_init(void)
 	proc_create_data("show_uid_stat", S_IWUGO, parent, &uid_stat_fops,
 					NULL);
 
-	thread_register_notifier(&process_notifier_block);
+	profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block);
 
 	return 0;
 }