test_power: Fix a bug in setting module parameter values

When the kernel loads a module, module params are processed prior to calling module_init. As a result, setting module param value should not have side effects, at least as long as the module has not been initialized. Signed-off-by: Andrey Gelman <andreyg@compulab.co.il> Signed-off-by: Anton Vorontsov <anton@enomsg.org>

test_power: Fix a bug in setting module parameter values
When the kernel loads a module, module params are processed prior to calling module_init. As a result, setting module param value should not have side effects, at least as long as the module has not been initialized. Signed-off-by: Andrey Gelman <andreyg@compulab.co.il> Signed-off-by: Anton Vorontsov <anton@enomsg.org>
Andrey Gelman · Anton Vorontsov
1 parent 6f8da5df8c
Showing 1 changed file with 21 additions and 10 deletions Side-by-side Diff
drivers/power/test_power.c
@@ -30,6 +30,8 @@
 static int battery_capacity		= 50;
 static int battery_voltage		= 3300;
  
+static bool module_initialized;
+
 static int test_power_get_ac_property(struct power_supply *psy,
 				      enum power_supply_property psp,
 				      union power_supply_propval *val)
@@ -185,6 +187,7 @@
 		}
 	}
  
+	module_initialized = true;
 	return 0;
 failed:
 	while (--i >= 0)
@@ -209,6 +212,8 @@
  
 	for (i = 0; i < ARRAY_SIZE(test_power_supplies); i++)
 		power_supply_unregister(&test_power_supplies[i]);
+
+	module_initialized = false;
 }
 module_exit(test_power_exit);
  
@@ -221,8 +226,8 @@
 };
  
 static struct battery_property_map map_ac_online[] = {
-	{ 0,  "on"  },
-	{ 1,  "off" },
+	{ 0,  "off"  },
+	{ 1,  "on" },
 	{ -1, NULL  },
 };
  
  
@@ -295,10 +300,16 @@
 	return def_key;
 }
  
+static inline void signal_power_supply_changed(struct power_supply *psy)
+{
+	if (module_initialized)
+		power_supply_changed(psy);
+}
+
 static int param_set_ac_online(const char *key, const struct kernel_param *kp)
 {
 	ac_online = map_get_value(map_ac_online, key, ac_online);
-	power_supply_changed(&test_power_supplies[0]);
+	signal_power_supply_changed(&test_power_supplies[0]);
 	return 0;
 }
  
@@ -311,7 +322,7 @@
 static int param_set_usb_online(const char *key, const struct kernel_param *kp)
 {
 	usb_online = map_get_value(map_ac_online, key, usb_online);
-	power_supply_changed(&test_power_supplies[2]);
+	signal_power_supply_changed(&test_power_supplies[2]);
 	return 0;
 }
  
@@ -325,7 +336,7 @@
 					const struct kernel_param *kp)
 {
 	battery_status = map_get_value(map_status, key, battery_status);
-	power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[1]);
 	return 0;
 }
  
@@ -339,7 +350,7 @@
 					const struct kernel_param *kp)
 {
 	battery_health = map_get_value(map_health, key, battery_health);
-	power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[1]);
 	return 0;
 }
  
@@ -353,7 +364,7 @@
 					const struct kernel_param *kp)
 {
 	battery_present = map_get_value(map_present, key, battery_present);
-	power_supply_changed(&test_power_supplies[0]);
+	signal_power_supply_changed(&test_power_supplies[0]);
 	return 0;
 }
  
@@ -369,7 +380,7 @@
 {
 	battery_technology = map_get_value(map_technology, key,
 						battery_technology);
-	power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[1]);
 	return 0;
 }
  
@@ -390,7 +401,7 @@
 		return -EINVAL;
  
 	battery_capacity = tmp;
-	power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[1]);
 	return 0;
 }
  
@@ -405,7 +416,7 @@
 		return -EINVAL;
  
 	battery_voltage = tmp;
-	power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[1]);
 	return 0;
 }
...	...	@@ -30,6 +30,8 @@
30	30	static int battery_capacity = 50;
31	31	static int battery_voltage = 3300;
32	32
	33	+static bool module_initialized;
	34	+
33	35	static int test_power_get_ac_property(struct power_supply *psy,
34	36	enum power_supply_property psp,
35	37	union power_supply_propval *val)
...	...	@@ -185,6 +187,7 @@
185	187	}
186	188	}
187	189
	190	+ module_initialized = true;
188	191	return 0;
189	192	failed:
190	193	while (--i >= 0)
...	...	@@ -209,6 +212,8 @@
209	212
210	213	for (i = 0; i < ARRAY_SIZE(test_power_supplies); i++)
211	214	power_supply_unregister(&test_power_supplies[i]);
	215	+
	216	+ module_initialized = false;
212	217	}
213	218	module_exit(test_power_exit);
214	219
...	...	@@ -221,8 +226,8 @@
221	226	};
222	227
223	228	static struct battery_property_map map_ac_online[] = {
224		- { 0, "on" },
225		- { 1, "off" },
	229	+ { 0, "off" },
	230	+ { 1, "on" },
226	231	{ -1, NULL },
227	232	};
228	233
229	234
...	...	@@ -295,10 +300,16 @@
295	300	return def_key;
296	301	}
297	302
	303	+static inline void signal_power_supply_changed(struct power_supply *psy)
	304	+{
	305	+ if (module_initialized)
	306	+ power_supply_changed(psy);
	307	+}
	308	+
298	309	static int param_set_ac_online(const char key, const struct kernel_param kp)
299	310	{
300	311	ac_online = map_get_value(map_ac_online, key, ac_online);
301		- power_supply_changed(&test_power_supplies[0]);
	312	+ signal_power_supply_changed(&test_power_supplies[0]);
302	313	return 0;
303	314	}
304	315
...	...	@@ -311,7 +322,7 @@
311	322	static int param_set_usb_online(const char key, const struct kernel_param kp)
312	323	{
313	324	usb_online = map_get_value(map_ac_online, key, usb_online);
314		- power_supply_changed(&test_power_supplies[2]);
	325	+ signal_power_supply_changed(&test_power_supplies[2]);
315	326	return 0;
316	327	}
317	328
...	...	@@ -325,7 +336,7 @@
325	336	const struct kernel_param *kp)
326	337	{
327	338	battery_status = map_get_value(map_status, key, battery_status);
328		- power_supply_changed(&test_power_supplies[1]);
	339	+ signal_power_supply_changed(&test_power_supplies[1]);
329	340	return 0;
330	341	}
331	342
...	...	@@ -339,7 +350,7 @@
339	350	const struct kernel_param *kp)
340	351	{
341	352	battery_health = map_get_value(map_health, key, battery_health);
342		- power_supply_changed(&test_power_supplies[1]);
	353	+ signal_power_supply_changed(&test_power_supplies[1]);
343	354	return 0;
344	355	}
345	356
...	...	@@ -353,7 +364,7 @@
353	364	const struct kernel_param *kp)
354	365	{
355	366	battery_present = map_get_value(map_present, key, battery_present);
356		- power_supply_changed(&test_power_supplies[0]);
	367	+ signal_power_supply_changed(&test_power_supplies[0]);
357	368	return 0;
358	369	}
359	370
...	...	@@ -369,7 +380,7 @@
369	380	{
370	381	battery_technology = map_get_value(map_technology, key,
371	382	battery_technology);
372		- power_supply_changed(&test_power_supplies[1]);
	383	+ signal_power_supply_changed(&test_power_supplies[1]);
373	384	return 0;
374	385	}
375	386
...	...	@@ -390,7 +401,7 @@
390	401	return -EINVAL;
391	402
392	403	battery_capacity = tmp;
393		- power_supply_changed(&test_power_supplies[1]);
	404	+ signal_power_supply_changed(&test_power_supplies[1]);
394	405	return 0;
395	406	}
396	407
...	...	@@ -405,7 +416,7 @@
405	416	return -EINVAL;
406	417
407	418	battery_voltage = tmp;
408		- power_supply_changed(&test_power_supplies[1]);
	419	+ signal_power_supply_changed(&test_power_supplies[1]);
409	420	return 0;
410	421	}
411	422