Compiation Err:Derefercing pointer to incomplete type

whenever i incude header uaccess.h for copy my compiler throws a lot of compilation errors . They are generaly of nature

uaccess.h>dereferencing pointer to incomplete type

sched.h>dereferncing pointer to incomplete type

i am using redhat 8.0
i have read that some distributions do not provide complete headers for module level programming Is that the reason for error i am getting ?

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