OT: calling kernel syscall manually

[guest01 <guest01@gmail.com>]

Hi

Sorry guys, this question is a little bit off topic, but maybe someone
has an answer, I am sure that there is a simple one. :-)

Ok, I have to find 3 possibilities to create a directory with 3 small c
programs:
1 -> using libc: mkdir(dir,mode)
2 -> using libcsyscall:  syscall(__NR_mkdir, "mkdirLibcSyscall", 0777);
3 -> using kernel directly

Ok, the third one is a little bit tricky, at least for me. I found an
example for lseek, but I don't know how to convert that for mkdir. I
don't know the necessary arguments, ..

> #include <linux/unistd.h>
> 
> _syscall5(int, _llseek, unsigned int, fd,
>           unsigned long, offset_high, unsigned long, offset_low,
>           long long *, result, unsigned int, origin)
> 
> long long
> my_llseek(unsigned int fd, unsigned long long offset, unsigned int origin) {
>           long long result;
>           int retval;
> 
>           retval = _llseek (fd, offset >> 32, offset & 0xffffffff,
>                             &result, origin);
>           return (retval == -1) ? -1 : result;
> }

Any help would be much appreciated. Thxs

regards
peda