#ifndef _ASM_X86_UACCESS_32_H #define _ASM_X86_UACCESS_32_H /* * User space memory access functions */ #include #include #include #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 (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); #ifndef DDE_LINUX /** * __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 the we don't result in page fault and sleep. * * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault * we return the initial request size (1, 2 or 4), as copy_*_user should do. * If a store crosses a page boundary and gets a fault, the x86 will not write * anything, so this is accurate. */ static __always_inline unsigned long __must_check __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) { if (__builtin_constant_p(n)) { unsigned long ret; switch (n) { case 1: __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1); return ret; case 2: __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2); return ret; case 4: __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4); return ret; } } 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. * * 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) { /* Avoid zeroing the tail if the copy fails.. * If 'n' is constant and 1, 2, or 4, we do still zero on a failure, * but as the zeroing behaviour is only significant when n is not * constant, that shouldn't be a problem. */ if (__builtin_constant_p(n)) { unsigned long ret; switch (n) { case 1: __get_user_size(*(u8 *)to, from, 1, ret, 1); return ret; case 2: __get_user_size(*(u16 *)to, from, 2, ret, 2); return ret; case 4: __get_user_size(*(u32 *)to, from, 4, ret, 4); return ret; } } 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. * * 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(); if (__builtin_constant_p(n)) { unsigned long ret; switch (n) { case 1: __get_user_size(*(u8 *)to, from, 1, ret, 1); return ret; case 2: __get_user_size(*(u16 *)to, from, 2, ret, 2); return ret; case 4: __get_user_size(*(u32 *)to, from, 4, ret, 4); return ret; } } return __copy_from_user_ll(to, from, n); } static __always_inline unsigned long __copy_from_user_nocache(void *to, const void __user *from, unsigned long n) { might_fault(); if (__builtin_constant_p(n)) { unsigned long ret; switch (n) { case 1: __get_user_size(*(u8 *)to, from, 1, ret, 1); return ret; case 2: __get_user_size(*(u16 *)to, from, 2, ret, 2); return ret; case 4: __get_user_size(*(u32 *)to, from, 4, ret, 4); return ret; } } return __copy_from_user_ll_nocache(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); } unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n); unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n); long __must_check strncpy_from_user(char *dst, const char __user *src, long count); long __must_check __strncpy_from_user(char *dst, const char __user *src, long count); #else /* DDE_LINUX */ /* use memcpy; "In both cases, the return value is the amount of memory still to be copied." */ static inline unsigned long __copy_to_user(void *to, const void *from, unsigned long n) { memcpy(to,from,n); return 0; } static inline unsigned long __copy_from_user(void *to, const void *from, unsigned long n) { memcpy(to,from,n); return 0; } static __always_inline unsigned long __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) { return __copy_from_user(to, from, n); } #endif /* DDE_LINUX */ /** * strlen_user: - Get the size of a string in user space. * @str: The string to measure. * * Context: User context only. This function may sleep. * * Get the size of a NUL-terminated string in user space. * * Returns the size of the string INCLUDING the terminating NUL. * On exception, returns 0. * * If there is a limit on the length of a valid string, you may wish to * consider using strnlen_user() instead. */ #define strlen_user(str) strnlen_user(str, LONG_MAX) long strnlen_user(const char __user *str, long n); unsigned long __must_check clear_user(void __user *mem, unsigned long len); unsigned long __must_check __clear_user(void __user *mem, unsigned long len); #endif /* _ASM_X86_UACCESS_32_H */