Add a #include <linux/types.h> to the-linux-kernel.h and let us know if it helps.
Does not help , now I get on top the other errors :
/work/crazy/VBox/stable/virtualbox/src/VirtualBox-1.5.2_OSE/include/iprt/types.h:121: error: redefinition of typedef 'bool'
/lib/modules/2.6.23-gcfa76f02/build/include/linux/types.h:33: error: previous declaration of 'bool' was here
...
/*
* C doesn't have bool.
*/
#ifndef __cplusplus
# if defined(__GNUC__)
# if defined(RT_OS_LINUX) && __GNUC__ < 3
typedef uint8_t bool;
# else
# if defined(RT_OS_DARWIN) && defined(_STDBOOL_H)
# undef bool
# endif
typedef _Bool bool; <- line 121
# endif
# else
typedef unsigned char bool;
# endif
# ifndef true
# define true (1)
# endif
# ifndef false
# define false (0)
# endif
#endif
Looking at include/iprt/types.h that has already #include <linux/types.h>.