#ifndef __LINUX_UACCESS_H__ #define __LINUX_UACCESS_H__ #include #ifndef ARCH_HAS_NOCACHE_UACCESS static inline unsigned long __copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long n) { return __copy_from_user_inatomic(to, from, n); } static inline unsigned long __copy_from_user_nocache(void *to, const void __user *from, unsigned long n) { return __copy_from_user(to, from, n); } #endif /* ARCH_HAS_NOCACHE_UACCESS */ /** * probe_kernel_address(): safely attempt to read from a location * @addr: address to read from - its type is type typeof(retval)* * @retval: read into this variable * * Safely read from address @addr into variable @revtal. If a kernel fault * happens, handle that and return -EFAULT. * We ensure that the __get_user() is executed in atomic context so that * do_page_fault() doesn't attempt to take mmap_sem. This makes * probe_kernel_address() suitable for use within regions where the caller * already holds mmap_sem, or other locks which nest inside mmap_sem. */ #define probe_kernel_address(addr, retval) \ ({ \ long ret; \ \ inc_preempt_count(); \ ret = __get_user(retval, addr); \ dec_preempt_count(); \ ret; \ }) #endif /* __LINUX_UACCESS_H__ */