Problem Description:
When making a ioctl(fd, EVIOCSFF) call from 32-bit program running on 64-bit arch I'm always receiving EINVAL. Further investigation lead to the cause:

Definition of the EVIOCSFF uses sizeof(struct ff_effect) which differs between 32-bit and 64-bit. 64-bit kernel does not recognize EVIOCSFF thus returning EINVAL.

Steps to reproduce:

A simple test program:

#include <linux/input.h>
#include <stdio.h>
int main(int argc, char * argv[])
{
     printf("sizeof(struct ff_effect) = %d EVIOCSFF=%#x\n", sizeof(struct ff_effect), EVIOCSFF);

     return 0;
}

$ gcc test_size.c -o test_size && ./test_size
sizeof(struct ff_effect) = 48 EVIOCSFF=0x40304580
$ gcc -m32 test_size.c -o test_size32 && ./test_size32
sizeof(struct ff_effect) = 44 EVIOCSFF=0x402c4580