in include/asm/uaccess.h [102:126]
static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
{
int retval = 0;
u32 tmp;
switch (size) {
case 1:
tmp = *(u8 *)x;
__put_user_asm_b(tmp, ptr, retval);
break;
case 2:
tmp = *(u16 *)x;
__put_user_asm_h(tmp, ptr, retval);
break;
case 4:
tmp = *(u32 *)x;
__put_user_asm_w(tmp, ptr, retval);
break;
case 8:
__put_user_asm_64(x, (u64 *)ptr, retval);
break;
}
return retval;
}