X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=mm%2Futil.c;h=7c122e49f769ccea98ae105746e0238acc1652ce;hb=c8935d773d14948f69fae7dd500b1f8e2f484775;hp=9341ca77bd88240741afbcbabed9019f247a7531;hpb=c4c0c56a7a85ed5725786219e4fbca7e840b1531;p=linux-2.6-omap-h63xx.git

diff --git a/mm/util.c b/mm/util.c
index 9341ca77bd8..7c122e49f76 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -69,6 +69,36 @@ void *kmemdup(const void *src, size_t len, gfp_t gfp)
 }
 EXPORT_SYMBOL(kmemdup);
 
+/**
+ * memdup_user - duplicate memory region from user space
+ *
+ * @src: source address in user space
+ * @len: number of bytes to copy
+ *
+ * Returns an ERR_PTR() on failure.
+ */
+void *memdup_user(const void __user *src, size_t len)
+{
+	void *p;
+
+	/*
+	 * Always use GFP_KERNEL, since copy_from_user() can sleep and
+	 * cause pagefault, which makes it pointless to use GFP_NOFS
+	 * or GFP_ATOMIC.
+	 */
+	p = kmalloc_track_caller(len, GFP_KERNEL);
+	if (!p)
+		return ERR_PTR(-ENOMEM);
+
+	if (copy_from_user(p, src, len)) {
+		kfree(p);
+		return ERR_PTR(-EFAULT);
+	}
+
+	return p;
+}
+EXPORT_SYMBOL(memdup_user);
+
 /**
  * __krealloc - like krealloc() but don't free @p.
  * @p: object to reallocate memory for.
@@ -129,6 +159,26 @@ void *krealloc(const void *p, size_t new_size, gfp_t flags)
 }
 EXPORT_SYMBOL(krealloc);
 
+/**
+ * kzfree - like kfree but zero memory
+ * @p: object to free memory of
+ *
+ * The memory of the object @p points to is zeroed before freed.
+ * If @p is %NULL, kzfree() does nothing.
+ */
+void kzfree(const void *p)
+{
+	size_t ks;
+	void *mem = (void *)p;
+
+	if (unlikely(ZERO_OR_NULL_PTR(mem)))
+		return;
+	ks = ksize(mem);
+	memset(mem, 0, ks);
+	kfree(mem);
+}
+EXPORT_SYMBOL(kzfree);
+
 /*
  * strndup_user - duplicate an existing string from user space
  * @s: The string to duplicate
@@ -171,3 +221,18 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
 	mm->unmap_area = arch_unmap_area;
 }
 #endif
+
+int __attribute__((weak)) get_user_pages_fast(unsigned long start,
+				int nr_pages, int write, struct page **pages)
+{
+	struct mm_struct *mm = current->mm;
+	int ret;
+
+	down_read(&mm->mmap_sem);
+	ret = get_user_pages(current, mm, start, nr_pages,
+					write, 0, pages, NULL);
+	up_read(&mm->mmap_sem);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(get_user_pages_fast);