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/**
* put_user: - Write a simple value into user space.
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
* Context: User context only. This function may sleep.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* data types like structures or arrays.
*
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
* to the result of dereferencing @ptr.
*
* Returns zero on success, or -EFAULT on error.
*/
#define put_user(x, ptr) \\
({ \\
int __ret_pu; \\
__typeof__(*(ptr)) __pu_val; \\
__chk_user_ptr(ptr); \\
might_fault(); \\
__pu_val = x; \\
switch (sizeof(*(ptr))) { \\
case 1: \\
__put_user_x(1, __pu_val, ptr, __ret_pu); \\
break; \\
case 2: \\
__put_user_x(2, __pu_val, ptr, __ret_pu); \\
break; \\
case 4: \\
__put_user_x(4, __pu_val, ptr, __ret_pu); \\
break; \\
case 8: \\
__put_user_x8(__pu_val, ptr, __ret_pu); \\
break; \\
default: \\
__put_user_x(X, __pu_val, ptr, __ret_pu); \\
break; \\
} \\
__ret_pu; \\
})