2 files changed, 32 insertions, 5 deletions

diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 1d534076d33a..08783eda9ce4 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -119,6 +119,12 @@ config PM_WAKELOCKS
         Allow user space to create, activate and deactivate wakeup source
         objects with the help of a sysfs-based interface.
 
+config PM_WAKELOCKS_LIMIT
+        int "Maximum number of user space wakeup sources (0 = no limit)"
+        range 0 100000
+        default 100
+        depends on PM_WAKELOCKS
+
 config PM_RUNTIME
         bool "Run-time PM core functionality"
         depends on !IA64_HP_SIM
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
index 579700665e8c..dc34b9d3b7d8 100644
--- a/kernel/power/wakelock.c
+++ b/kernel/power/wakelock.c
@@ -17,7 +17,6 @@
 #include <linux/rbtree.h>
 #include <linux/slab.h>
 
-#define WL_NUMBER_LIMIT 100
 #define WL_GC_COUNT_MAX 100
 #define WL_GC_TIME_SEC  300
 
@@ -32,7 +31,6 @@ struct wakelock {
 
 static struct rb_root wakelocks_tree = RB_ROOT;
 static LIST_HEAD(wakelocks_lru_list);
-static unsigned int number_of_wakelocks;
 static unsigned int wakelocks_gc_count;
 
 ssize_t pm_show_wakelocks(char *buf, bool show_active)
@@ -58,6 +56,29 @@ ssize_t pm_show_wakelocks(char *buf, bool show_active)
         return (str - buf);
 }
 
+#if CONFIG_PM_WAKELOCKS_LIMIT > 0
+static unsigned int number_of_wakelocks;
+
+static inline bool wakelocks_limit_exceeded(void)
+{
+        return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT;
+}
+
+static inline void increment_wakelocks_number(void)
+{
+        number_of_wakelocks++;
+}
+
+static inline void decrement_wakelocks_number(void)
+{
+        number_of_wakelocks--;
+}
+#else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */
+static inline bool wakelocks_limit_exceeded(void) { return false; }
+static inline void increment_wakelocks_number(void) {}
+static inline void decrement_wakelocks_number(void) {}
+#endif /* CONFIG_PM_WAKELOCKS_LIMIT */
+
 static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
                                             bool add_if_not_found)
 {
@@ -85,7 +106,7 @@ static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
         if (!add_if_not_found)
                 return ERR_PTR(-EINVAL);
 
-        if (number_of_wakelocks > WL_NUMBER_LIMIT)
+        if (wakelocks_limit_exceeded())
                 return ERR_PTR(-ENOSPC);
 
         /* Not found, we have to add a new one. */
@@ -103,7 +124,7 @@ static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
         rb_link_node(&wl->node, parent, node);
         rb_insert_color(&wl->node, &wakelocks_tree);
         list_add(&wl->lru, &wakelocks_lru_list);
-        number_of_wakelocks++;
+        increment_wakelocks_number();
         return wl;
 }
 
@@ -175,7 +196,7 @@ static void wakelocks_gc(void)
                         list_del(&wl->lru);
                         kfree(wl->name);
                         kfree(wl);
-                        number_of_wakelocks--;
+                        decrement_wakelocks_number();
                 }
         }
         wakelocks_gc_count = 0;