SYSCALL_DEFINE3 宏定义的转换

SYSCALL_DEFINE3 在何处定义？

#define SYSCALL_DEFINE3(name, ...)

       SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)

#define SYSCALL_DEFINEx(x, sname, ...)                                /
        __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)

#define __SYSCALL_DEFINEx(x, name, ...)                                        /
        asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__))

 

 

include/linux/syscalls.h, line 228

#define __SYSCALL_DEFINEx
(x
, name
, ...)                                 /

    asmlinkage
 long sys
##name(__SC_DECL##x(__VA_ARGS__))


#define __SC_DECL3
(t3
, a3
, ...) t3
 a3
, __SC_DECL2
(__VA_ARGS__)

所以对函数定义 SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol) 就等于

 SYSCALL_DEFINEx(3, _##socket, __VA_ARGS__)

= asmlinkage long sys_socket(__SC_DECL3(__VA_ARGS__))

= asmlinkage long sys_socket(int family, __SC_DECL2(__VA_ARGS__))

最终得到

asmlinkage long sys_socket(int family, int type, int protocol)