[PATCH] introduce and use kzalloc

This patch introduces a kzalloc wrapper and converts kernel/ to use it.  It
saves a little program text.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

include/linux/slab.h

@@ -99,7 +99,21 @@ static inline void *kmalloc(size_t size, unsigned int __nocast flags)
 	return __kmalloc(size, flags);
 }
 
-extern void *kcalloc(size_t, size_t, unsigned int __nocast);
+extern void *kzalloc(size_t, unsigned int __nocast);
+
+/**
+ * kcalloc - allocate memory for an array. The memory is set to zero.
+ * @n: number of elements.
+ * @size: element size.
+ * @flags: the type of memory to allocate.
+ */
+static inline void *kcalloc(size_t n, size_t size, unsigned int __nocast flags)
+{
+	if (n != 0 && size > INT_MAX / n)
+		return NULL;
+	return kzalloc(n * size, flags);
+}
+
 extern void kfree(const void *);
 extern unsigned int ksize(const void *);
 

kernel/intermodule.c

@@ -39,7 +39,7 @@ void inter_module_register(const char *im_name, struct module *owner, const void
 	struct list_head *tmp;
 	struct inter_module_entry *ime, *ime_new;
 
-	if (!(ime_new = kmalloc(sizeof(*ime), GFP_KERNEL))) {
+	if (!(ime_new = kzalloc(sizeof(*ime), GFP_KERNEL))) {
 		/* Overloaded kernel, not fatal */
 		printk(KERN_ERR
 			"Aiee, inter_module_register: cannot kmalloc entry for '%s'\n",
@@ -47,7 +47,6 @@ void inter_module_register(const char *im_name, struct module *owner, const void
 		kmalloc_failed = 1;
 		return;
 	}
-	memset(ime_new, 0, sizeof(*ime_new));
 	ime_new->im_name = im_name;
 	ime_new->owner = owner;
 	ime_new->userdata = userdata;

kernel/params.c

@@ -542,8 +542,8 @@ static void __init kernel_param_sysfs_setup(const char *name,
 {
 	struct module_kobject *mk;
 
-	mk = kmalloc(sizeof(struct module_kobject), GFP_KERNEL);
-	memset(mk, 0, sizeof(struct module_kobject));
+	mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
+	BUG_ON(!mk);
 
 	mk->mod = THIS_MODULE;
 	kobj_set_kset_s(mk, module_subsys);

kernel/power/pm.c

@@ -60,9 +60,8 @@ struct pm_dev *pm_register(pm_dev_t type,
 			   unsigned long id,
 			   pm_callback callback)
 {
-	struct pm_dev *dev = kmalloc(sizeof(struct pm_dev), GFP_KERNEL);
+	struct pm_dev *dev = kzalloc(sizeof(struct pm_dev), GFP_KERNEL);
 	if (dev) {
-		memset(dev, 0, sizeof(*dev));
 		dev->type = type;
 		dev->id = id;
 		dev->callback = callback;

kernel/resource.c

@@ -430,10 +430,9 @@ EXPORT_SYMBOL(adjust_resource);
  */
 struct resource * __request_region(struct resource *parent, unsigned long start, unsigned long n, const char *name)
 {
-	struct resource *res = kmalloc(sizeof(*res), GFP_KERNEL);
+	struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 
 	if (res) {
-		memset(res, 0, sizeof(*res));
 		res->name = name;
 		res->start = start;
 		res->end = start + n - 1;

kernel/workqueue.c

@@ -308,10 +308,9 @@ struct workqueue_struct *__create_workqueue(const char *name,
 	struct workqueue_struct *wq;
 	struct task_struct *p;
 
-	wq = kmalloc(sizeof(*wq), GFP_KERNEL);
+	wq = kzalloc(sizeof(*wq), GFP_KERNEL);
 	if (!wq)
 		return NULL;
-	memset(wq, 0, sizeof(*wq));
 
 	wq->name = name;
 	/* We don't need the distraction of CPUs appearing and vanishing. */

mm/slab.c

@@ -2558,24 +2558,18 @@ void kmem_cache_free(kmem_cache_t *cachep, void *objp)
 EXPORT_SYMBOL(kmem_cache_free);
 
 /**
- * kcalloc - allocate memory for an array. The memory is set to zero.
- * @n: number of elements.
- * @size: element size.
+ * kzalloc - allocate memory. The memory is set to zero.
+ * @size: how many bytes of memory are required.
  * @flags: the type of memory to allocate.
  */
-void *kcalloc(size_t n, size_t size, unsigned int __nocast flags)
+void *kzalloc(size_t size, unsigned int __nocast flags)
 {
-	void *ret = NULL;
-
-	if (n != 0 && size > INT_MAX / n)
-		return ret;
-
-	ret = kmalloc(n * size, flags);
+	void *ret = kmalloc(size, flags);
 	if (ret)
-		memset(ret, 0, n * size);
+		memset(ret, 0, size);
 	return ret;
 }
-EXPORT_SYMBOL(kcalloc);
+EXPORT_SYMBOL(kzalloc);
 
 /**
  * kfree - free previously allocated memory