arch/powerpc/lib/checksum_wrappers.c

   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         might_sleep();
  20
  21         if (unlikely(!access_ok(src, len)))
  22                 return 0;
  23
  24         allow_read_from_user(src, len);
  25
  26         csum = csum_partial_copy_generic((void __force *)src, dst, len);
  27
  28         prevent_read_from_user(src, len);
  29         return csum;
  30 }
  31 EXPORT_SYMBOL(csum_and_copy_from_user);
  32
  33 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
  34 {
  35         __wsum csum;
  36
  37         might_sleep();
  38         if (unlikely(!access_ok(dst, len)))
  39                 return 0;
  40
  41         allow_write_to_user(dst, len);
  42
  43         csum = csum_partial_copy_generic(src, (void __force *)dst, len);
  44
  45         prevent_write_to_user(dst, len);
  46         return csum;
  47 }
  48 EXPORT_SYMBOL(csum_and_copy_to_user);