Howdy,
I've tried googling for this, and searched the archives as well, but I
haven't found a satisfactory answer. My apologies if this is covered
somewhere...
The kernel's linux/types.h resolves mode_t to __kernel_mode_t which is
then defined as:
typedef unsigned short __kernel_mode_t;
in linux/posix_types.h.
However, glibc's sys/types.h eventually (in bits/typesizes.h) resolves
mode_t to:
#define __MODE_T_TYPE __U32_TYPE
So, when I try to pass a mode_t type from kernel space to user space,
the kernel sends a short when the user space expects an int. I of
course declare my variable as 'mode_t' both in my kernel module and in
my user-space app., with the above inconsistency.
I can get around this easily enough by sending/receiving __u32, but I'm
trying to be a little more type-safe...
Is this something that is intentional, or is this an inconsistency
between linux and glibc? I've verified this both on 2.6.16.47 and
2.6.20.6. Any ideas?
Thanks,
John