[LTP] [PATCH] fcntl36: fix 32-bit sporadic failures

[Jan Stancek <jstancek@redhat.com>]

----- Original Message -----
> Jan,
> 
> Running in a container, armhf userland, with arm64 kernel (real HW: hikey):
> 
> $ uname -a
> Linux ltpfcntl36 4.16.0-2-arm64 #1 SMP Debian 4.16.12-1 (2018-05-27)
> armv8l GNU/Linux
> 
> $ file ./fcntl36
> ./fcntl36: ELF 32-bit LSB pie executable ARM, EABI5 version 1 (SYSV),
> dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for
> GNU/Linux 3.2.0,
> BuildID[sha1]=074ba3622d50f62108260d2912ae5dc0e8d52d46, with
> debug_info, not stripped
> 
> My un-patched binary shows me:
> 
> [pid  3501] fcntl64(11, F_OFD_SETLK, {l_type=F_UNLCK,
> l_whence=SEEK_SET, l_start=16384, l_len=4096} <unfinished ...>
> 
> no F_SETLK for this binary.
> 
> Running in a container, arm64 userland, with arm64 kernel (real HW: hikey):
> 
> $ file ./fcntl36
> ./fcntl36: ELF 64-bit LSB pie executable ARM aarch64, version 1
> (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1,
> for GNU/Linux 3.7.0,
> BuildID[sha1]=8fb1d0e0e0d027fce5c8d11742ce5bdb7678749b, with
> debug_info, not stripped
> 
> Same un-patched binary shows me:
> 
> [pid   483] fcntl(10, F_OFD_SETLKW, {l_type=F_UNLCK,
> l_whence=SEEK_SET, l_start=13312, l_len=4096} <unfinished ...>
> 
> Do you want me to test patched LTP in arm32/64 to make sure they work

Yes, if possible test patched LTP in environment which
is known to hit the failure.

> and you check if it fixes the issue for i686 on your side ?

I already did, it does eliminate problem for me.

> Or should
> I compile it some other way ?

Default build is OK. Apply patch, build and see if
you can reproduce the failure.

> 
> Let me know what you need.
> 
> Rafael
> 
> On 15 June 2018 at 14:22, Jan Stancek <jstancek@redhat.com> wrote:
> 
> > No kernel bug, problem was found in my reproducer.
> > Can anyone confirm this fixes 32-bit arm too?
>