#ifndef _ASM_X86_UACCESS_32_H #define _ASM_X86_UACCESS_32_H /* * User space memory access functions */ #include #include #include unsigned long __must_check __copy_to_user_ll (void __user *to, const void *from, unsigned long n); unsigned long __must_check __copy_from_user_ll (void *to, const void __user *from, unsigned long n); unsigned long __must_check __copy_from_user_ll_nozero (void *to, const void __user *from, unsigned long n); unsigned long __must_check __copy_from_user_ll_nocache_nozero (void *to, const void __user *from, unsigned long n); /** * __copy_to_user_inatomic: - Copy a block of data into user space, with less checking. * @to: Destination address, in user space. * @from: Source address, in kernel space. * @n: Number of bytes to copy. * * Context: User context only. * * Copy data from kernel space to user space. Caller must check * the specified block with access_ok() before calling this function. * The caller should also make sure he pins the user space address * so that we don't result in page fault and sleep. */ static __always_inline unsigned long __must_check __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) { check_object_size(from, n, true); return __copy_to_user_ll(to, from, n); } /** * __copy_to_user: - Copy a block of data into user space, with less checking. * @to: Destination address, in user space. * @from: Source address, in kernel space. * @n: Number of bytes to copy. * * Context: User context only. This function may sleep if pagefaults are * enabled. * * Copy data from kernel space to user space. Caller must check * the specified block with access_ok() before calling this function. * * Returns number of bytes that could not be copied. * On success, this will be zero. */ static __always_inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n) { might_fault(); return __copy_to_user_inatomic(to, from, n); } static __always_inline unsigned long __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) { return __copy_from_user_ll_nozero(to, from, n); } /** * __copy_from_user: - Copy a block of data from user space, with less checking. * @to: Destination address, in kernel space. * @from: Source address, in user space. * @n: Number of bytes to copy. * * Context: User context only. This function may sleep if pagefaults are * enabled. * * Copy data from user space to kernel space. Caller must check * the specified block with access_ok() before calling this function. * * Returns number of bytes that could not be copied. * On success, this will be zero. * * If some data could not be copied, this function will pad the copied * data to the requested size using zero bytes. * * An alternate version - __copy_from_user_inatomic() - may be called from * atomic context and will fail rather than sleep. In this case the * uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h * for explanation of why this is needed. */ static __always_inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) { might_fault(); check_object_size(to, n, false); if (__builtin_constant_p(n)) { unsigned long ret; switch (n) { case 1: __uaccess_begin(); __get_user_size(*(u8 *)to, from, 1, ret, 1); __uaccess_end(); return ret; case 2: __uaccess_begin(); __get_user_size(*(u16 *)to, from, 2, ret, 2); __uaccess_end(); return ret; case 4: __uaccess_begin(); __get_user_size(*(u32 *)to, from, 4, ret, 4); __uaccess_end(); return ret; } } return __copy_from_user_ll(to, from, n); } static __always_inline unsigned long __copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long n) { return __copy_from_user_ll_nocache_nozero(to, from, n); } #endif /* _ASM_X86_UACCESS_32_H */