Merge branch 'x86/core' into x86/mce2

1 files changed, 14 insertions, 2 deletions

diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 84210c479fc..987a2c10fe2 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -192,14 +192,26 @@ static inline int __copy_from_user_nocache(void *dst, const void __user *src,
 					   unsigned size)
 {
 	might_sleep();
-	return __copy_user_nocache(dst, src, size, 1);
+	/*
+	 * In practice this limit means that large file write()s
+	 * which get chunked to 4K copies get handled via
+	 * non-temporal stores here. Smaller writes get handled
+	 * via regular __copy_from_user():
+	 */
+	if (likely(size >= PAGE_SIZE))
+		return __copy_user_nocache(dst, src, size, 1);
+	else
+		return __copy_from_user(dst, src, size);
 }
 
 static inline int __copy_from_user_inatomic_nocache(void *dst,
 						    const void __user *src,
 						    unsigned size)
 {
-	return __copy_user_nocache(dst, src, size, 0);
+	if (likely(size >= PAGE_SIZE))
+		return __copy_user_nocache(dst, src, size, 0);
+	else
+		return __copy_from_user_inatomic(dst, src, size);
 }
 
 unsigned long