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#ifndef __LINUX_UACCESS_H__
#define __LINUX_UACCESS_H__
#include <asm/uaccess.h>
#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, (__force typeof(*addr) __user *)addr);\
dec_preempt_count(); \
ret; \
})
#endif /* __LINUX_UACCESS_H__ */
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