wrapper/kstrtox.h

   1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
   2  *
   3  * wrapper/kstrtox.h
   4  *
   5  * Copyright (C) 2015 Michael Jeanson <mjeanson@efficios.com>
   6  */
   7
   8 #ifndef _LTTNG_WRAPPER_KSTRTOX_H
   9 #define _LTTNG_WRAPPER_KSTRTOX_H
  10
  11 #include <linux/version.h>
  12
  13 #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,0,0))
  14
  15 #include <linux/uaccess.h>
  16
  17 /* Excludes final \0. */
  18 #define LTTNG_MAX_UINT_CHAR 10
  19
  20 static inline
  21 int __must_check lttng_kstrtouint_from_user(const char __user *ubuf,
  22                 size_t count, unsigned int base, unsigned int *res)
  23 {
  24         unsigned int _res;
  25         char kbuf[LTTNG_MAX_UINT_CHAR + 1], *endptr;
  26
  27         memset(kbuf, 0, sizeof(kbuf));
  28         if (copy_from_user(kbuf, ubuf, min_t(size_t, LTTNG_MAX_UINT_CHAR, count)))
  29                 return -EFAULT;
  30
  31         _res = simple_strtoul(kbuf, &endptr, base);
  32         if (!endptr)
  33                 return -EINVAL;
  34
  35         *res = _res;
  36         return 0;
  37 }
  38 #else
  39 static inline
  40 int __must_check lttng_kstrtouint_from_user(const char __user *ubuf,
  41                 size_t count, unsigned int base, unsigned int *res)
  42 {
  43         return kstrtouint_from_user(ubuf, count, base, res);
  44 }
  45 #endif
  46
  47 #endif /* _LTTNG_WRAPPER_KSTRTOX_H */