315 строки
7.2 KiB
C
315 строки
7.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_GENERIC_UACCESS_H
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#define __ASM_GENERIC_UACCESS_H
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/*
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* User space memory access functions, these should work
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* on any machine that has kernel and user data in the same
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* address space, e.g. all NOMMU machines.
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*/
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#include <linux/string.h>
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#ifdef CONFIG_UACCESS_MEMCPY
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#include <asm/unaligned.h>
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static __always_inline int
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__get_user_fn(size_t size, const void __user *from, void *to)
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{
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BUILD_BUG_ON(!__builtin_constant_p(size));
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switch (size) {
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case 1:
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*(u8 *)to = get_unaligned((u8 __force *)from);
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return 0;
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case 2:
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*(u16 *)to = get_unaligned((u16 __force *)from);
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return 0;
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case 4:
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*(u32 *)to = get_unaligned((u32 __force *)from);
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return 0;
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case 8:
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*(u64 *)to = get_unaligned((u64 __force *)from);
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return 0;
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default:
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BUILD_BUG();
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return 0;
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}
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}
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#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
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static __always_inline int
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__put_user_fn(size_t size, void __user *to, void *from)
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{
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BUILD_BUG_ON(!__builtin_constant_p(size));
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switch (size) {
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case 1:
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put_unaligned(*(u8 *)from, (u8 __force *)to);
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return 0;
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case 2:
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put_unaligned(*(u16 *)from, (u16 __force *)to);
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return 0;
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case 4:
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put_unaligned(*(u32 *)from, (u32 __force *)to);
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return 0;
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case 8:
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put_unaligned(*(u64 *)from, (u64 __force *)to);
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return 0;
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default:
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BUILD_BUG();
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return 0;
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}
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}
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#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
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#define __get_kernel_nofault(dst, src, type, err_label) \
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do { \
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*((type *)dst) = get_unaligned((type *)(src)); \
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if (0) /* make sure the label looks used to the compiler */ \
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goto err_label; \
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} while (0)
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#define __put_kernel_nofault(dst, src, type, err_label) \
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do { \
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put_unaligned(*((type *)src), (type *)(dst)); \
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if (0) /* make sure the label looks used to the compiler */ \
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goto err_label; \
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} while (0)
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#define HAVE_GET_KERNEL_NOFAULT 1
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static inline __must_check unsigned long
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raw_copy_from_user(void *to, const void __user * from, unsigned long n)
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{
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memcpy(to, (const void __force *)from, n);
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return 0;
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}
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static inline __must_check unsigned long
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raw_copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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memcpy((void __force *)to, from, n);
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return 0;
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}
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#define INLINE_COPY_FROM_USER
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#define INLINE_COPY_TO_USER
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#endif /* CONFIG_UACCESS_MEMCPY */
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#ifdef CONFIG_SET_FS
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#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
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#ifndef KERNEL_DS
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#define KERNEL_DS MAKE_MM_SEG(~0UL)
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#endif
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#ifndef USER_DS
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#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
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#endif
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#ifndef get_fs
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#define get_fs() (current_thread_info()->addr_limit)
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static inline void set_fs(mm_segment_t fs)
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{
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current_thread_info()->addr_limit = fs;
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}
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#endif
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#ifndef uaccess_kernel
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#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
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#endif
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#endif /* CONFIG_SET_FS */
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#define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))
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/*
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* The architecture should really override this if possible, at least
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* doing a check on the get_fs()
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*/
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#ifndef __access_ok
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static inline int __access_ok(unsigned long addr, unsigned long size)
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{
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return 1;
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}
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#endif
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/*
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* These are the main single-value transfer routines. They automatically
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* use the right size if we just have the right pointer type.
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* This version just falls back to copy_{from,to}_user, which should
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* provide a fast-path for small values.
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*/
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#define __put_user(x, ptr) \
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({ \
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__typeof__(*(ptr)) __x = (x); \
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int __pu_err = -EFAULT; \
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__chk_user_ptr(ptr); \
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switch (sizeof (*(ptr))) { \
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case 1: \
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case 2: \
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case 4: \
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case 8: \
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__pu_err = __put_user_fn(sizeof (*(ptr)), \
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ptr, &__x); \
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break; \
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default: \
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__put_user_bad(); \
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break; \
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} \
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__pu_err; \
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})
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#define put_user(x, ptr) \
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({ \
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void __user *__p = (ptr); \
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might_fault(); \
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access_ok(__p, sizeof(*ptr)) ? \
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__put_user((x), ((__typeof__(*(ptr)) __user *)__p)) : \
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-EFAULT; \
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})
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#ifndef __put_user_fn
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static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
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{
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return unlikely(raw_copy_to_user(ptr, x, size)) ? -EFAULT : 0;
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}
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#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
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#endif
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extern int __put_user_bad(void) __attribute__((noreturn));
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#define __get_user(x, ptr) \
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({ \
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int __gu_err = -EFAULT; \
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__chk_user_ptr(ptr); \
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switch (sizeof(*(ptr))) { \
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case 1: { \
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unsigned char __x = 0; \
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__gu_err = __get_user_fn(sizeof (*(ptr)), \
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ptr, &__x); \
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \
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break; \
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}; \
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case 2: { \
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unsigned short __x = 0; \
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__gu_err = __get_user_fn(sizeof (*(ptr)), \
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ptr, &__x); \
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \
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break; \
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}; \
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case 4: { \
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unsigned int __x = 0; \
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__gu_err = __get_user_fn(sizeof (*(ptr)), \
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ptr, &__x); \
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \
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break; \
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}; \
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case 8: { \
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unsigned long long __x = 0; \
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__gu_err = __get_user_fn(sizeof (*(ptr)), \
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ptr, &__x); \
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \
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break; \
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}; \
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default: \
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__get_user_bad(); \
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break; \
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} \
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__gu_err; \
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})
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#define get_user(x, ptr) \
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({ \
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const void __user *__p = (ptr); \
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might_fault(); \
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access_ok(__p, sizeof(*ptr)) ? \
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__get_user((x), (__typeof__(*(ptr)) __user *)__p) :\
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((x) = (__typeof__(*(ptr)))0,-EFAULT); \
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})
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#ifndef __get_user_fn
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static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
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{
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return unlikely(raw_copy_from_user(x, ptr, size)) ? -EFAULT : 0;
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}
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#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
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#endif
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extern int __get_user_bad(void) __attribute__((noreturn));
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/*
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* Copy a null terminated string from userspace.
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*/
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#ifndef __strncpy_from_user
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static inline long
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__strncpy_from_user(char *dst, const char __user *src, long count)
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{
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char *tmp;
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strncpy(dst, (const char __force *)src, count);
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for (tmp = dst; *tmp && count > 0; tmp++, count--)
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;
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return (tmp - dst);
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}
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#endif
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static inline long
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strncpy_from_user(char *dst, const char __user *src, long count)
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{
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if (!access_ok(src, 1))
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return -EFAULT;
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return __strncpy_from_user(dst, src, count);
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}
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/*
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* Return the size of a string (including the ending 0)
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*
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* Return 0 on exception, a value greater than N if too long
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*/
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#ifndef __strnlen_user
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#define __strnlen_user(s, n) (strnlen((s), (n)) + 1)
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#endif
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/*
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* Unlike strnlen, strnlen_user includes the nul terminator in
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* its returned count. Callers should check for a returned value
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* greater than N as an indication the string is too long.
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*/
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static inline long strnlen_user(const char __user *src, long n)
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{
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if (!access_ok(src, 1))
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return 0;
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return __strnlen_user(src, n);
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}
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/*
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* Zero Userspace
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*/
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#ifndef __clear_user
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static inline __must_check unsigned long
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__clear_user(void __user *to, unsigned long n)
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{
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memset((void __force *)to, 0, n);
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return 0;
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}
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#endif
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static inline __must_check unsigned long
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clear_user(void __user *to, unsigned long n)
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{
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might_fault();
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if (!access_ok(to, n))
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return n;
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return __clear_user(to, n);
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}
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#include <asm/extable.h>
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#endif /* __ASM_GENERIC_UACCESS_H */
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