[LTP] [PATCH] syscalls/fcntl34: use struct flock64 on 32bit

[Cyril Hrubis]

Hi!
> > Since both manual and glibc examples use struct flock with OFD locks in
> > examples and if I compile glibc example for OFD locks[1] on 32bit system
> > garbage is passed to kernel syscalls and the program hangs, so I would
> > call this glibc/kernel bug.
> > 
> > I would expect glibc to convert the flock structure to 64 bit one
> > silently in this case.
> 
> That might not be possible as such "silent" conversion could break
> a lot of existing programs that rely on hardcoded 32bit struct flock
> size.

What I meant was to use the user supplied flock structure to initialize
flock64 before doing the syscall. We would have to copy the l_type back
in case of FGETLK but apart from that I do not see any problem with
this.

Also I've tried to run the test on purely 32bit machine (i686 openSUSE
Tumbleweed) and the problem seems to be present there as well. I can see
that it calls fcntl64() which fails with EINVAL and both l_start and
l_len are clearly garbage. So 32bit glibc with 32bit kernel seems to be
broken as well.

-- 
Cyril Hrubis
chrubis@suse.cz