[next:akpm 16/51] drivers/thermal/cpu_cooling.c:461:6-17: ERROR: iterator variable bound on line 460 cannot be NULL

[Fengguang Wu <fengguang.wu@xxxxxxxxx>]

Hi Amit,

There are new coccinelle warnings show up in

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm
head:   6a015080d00181e3a650d51e078ea14be82abfc4
commit: 24c8a66b8a75ed71806695fc232fb9499a7f672d [16/51] thermal: add generic cpufreq cooling implementation

All coccinelle warnings:

+ drivers/thermal/cpu_cooling.c:461:6-17: ERROR: iterator variable bound on line 460 cannot be NULL
  drivers/thermal/cpu_cooling.c:323:6-20: ERROR: iterator variable bound on line 322 cannot be NULL
  drivers/thermal/cpu_cooling.c:300:6-20: ERROR: iterator variable bound on line 299 cannot be NULL
  drivers/thermal/cpu_cooling.c:346:6-20: ERROR: iterator variable bound on line 345 cannot be NULL

vim +461 drivers/thermal/cpu_cooling.c
   458	
   459		mutex_lock(&cooling_cpufreq_lock);
   460		list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) {
 > 461			if (cpufreq_dev && cpufreq_dev->cool_dev == cdev)
   462				break;
   463			cpufreq_dev_count++;
   464		}

Please fold the attached patch if you agree with the warnings.

---
0-DAY kernel build testing backend         Open Source Technology Centre
Fengguang Wu <wfg@xxxxxxxxxxxxxxx>                     Intel Corporation

Generated by: iterators/itnull.cocci

 Many iterators have the property that the first argument is always bound
 to a real list element, never NULL.

Semantic patch information:
 False positives arise for some iterators that do not have this property,
 or in cases when the loop cursor is reassigned.  The latter should only
 happen when the matched code is on the way to a loop exit (break, goto,
 or return).

--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -297,7 +297,7 @@ static int cpufreq_get_max_state(struct
 
 	mutex_lock(&cooling_cpufreq_lock);
 	list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) {
-		if (cpufreq_device && cpufreq_device->cool_dev == cdev) {
+		if (cpufreq_device->cool_dev == cdev) {
 			*state = cpufreq_device->tab_size;
 			ret = 0;
 			break;
@@ -320,7 +320,7 @@ static int cpufreq_get_cur_state(struct
 
 	mutex_lock(&cooling_cpufreq_lock);
 	list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) {
-		if (cpufreq_device && cpufreq_device->cool_dev == cdev) {
+		if (cpufreq_device->cool_dev == cdev) {
 			*state = cpufreq_device->cpufreq_state;
 			ret = 0;
 			break;
@@ -343,7 +343,7 @@ static int cpufreq_set_cur_state(struct
 
 	mutex_lock(&cooling_cpufreq_lock);
 	list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) {
-		if (cpufreq_device && cpufreq_device->cool_dev == cdev) {
+		if (cpufreq_device->cool_dev == cdev) {
 			ret = 0;
 			break;
 		}
@@ -458,7 +458,7 @@ void cpufreq_cooling_unregister(struct t
 
 	mutex_lock(&cooling_cpufreq_lock);
 	list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) {
-		if (cpufreq_dev && cpufreq_dev->cool_dev == cdev)
+		if (cpufreq_dev->cool_dev == cdev)
 			break;
 		cpufreq_dev_count++;
 	}