1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Copyright (C) IBM Corporation, 2010 5 * 6 * Author: Anton Blanchard <anton@au.ibm.com> 7 */ 8 #include <linux/export.h> 9 #include <linux/compiler.h> 10 #include <linux/types.h> 11 #include <asm/checksum.h> 12 #include <linux/uaccess.h> 13 14 __wsum csum_and_copy_from_user(const void __user *src, void *dst, 15 int len) 16 { 17 __wsum csum; 18 19 if (unlikely(!user_read_access_begin(src, len))) 20 return 0; 21 22 csum = csum_partial_copy_generic((void __force *)src, dst, len); 23 24 user_read_access_end(); 25 return csum; 26 } 27 EXPORT_SYMBOL(csum_and_copy_from_user); 28 29 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len) 30 { 31 __wsum csum; 32 33 if (unlikely(!user_write_access_begin(dst, len))) 34 return 0; 35 36 csum = csum_partial_copy_generic(src, (void __force *)dst, len); 37 38 user_write_access_end(); 39 return csum; 40 } 41 EXPORT_SYMBOL(csum_and_copy_to_user); 42