include/asm/uaccess.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
0004  * Copyright (C) 2015 Richard Weinberger (richard@nod.at)
0005  */
0006
0007 #ifndef __UM_UACCESS_H
0008 #define __UM_UACCESS_H
0009
0010 #include <asm/elf.h>
0011 #include <asm/unaligned.h>
0012
0013 #define __under_task_size(addr, size) \
0014     (((unsigned long) (addr) < TASK_SIZE) && \
0015      (((unsigned long) (addr) + (size)) < TASK_SIZE))
0016
0017 #define __access_ok_vsyscall(addr, size) \
0018       (((unsigned long) (addr) >= FIXADDR_USER_START) && \
0019       ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
0020       ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
0021
0022 #define __addr_range_nowrap(addr, size) \
0023     ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
0024
0025 extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
0026 extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
0027 extern unsigned long __clear_user(void __user *mem, unsigned long len);
0028 static inline int __access_ok(const void __user *ptr, unsigned long size);
0029
0030 /* Teach asm-generic/uaccess.h that we have C functions for these. */
0031 #define __access_ok __access_ok
0032 #define __clear_user __clear_user
0033
0034 #define INLINE_COPY_FROM_USER
0035 #define INLINE_COPY_TO_USER
0036
0037 #include <asm-generic/uaccess.h>
0038
0039 static inline int __access_ok(const void __user *ptr, unsigned long size)
0040 {
0041     unsigned long addr = (unsigned long)ptr;
0042     return __addr_range_nowrap(addr, size) &&
0043         (__under_task_size(addr, size) ||
0044          __access_ok_vsyscall(addr, size));
0045 }
0046
0047 /* no pagefaults for kernel addresses in um */
0048 #define __get_kernel_nofault(dst, src, type, err_label)         \
0049 do {                                    \
0050     *((type *)dst) = get_unaligned((type *)(src));          \
0051     if (0) /* make sure the label looks used to the compiler */ \
0052         goto err_label;                     \
0053 } while (0)
0054
0055 #define __put_kernel_nofault(dst, src, type, err_label)         \
0056 do {                                    \
0057     put_unaligned(*((type *)src), (type *)(dst));           \
0058     if (0) /* make sure the label looks used to the compiler */ \
0059         goto err_label;                     \
0060 } while (0)
0061
0062 #endif