Re: [PATCH v2] fcntl: don't cap l_start and l_end values for F_GETLK64 in compat syscall

[Christoph Hellwig]

On Wed, Nov 15, 2017 at 01:03:45PM -0500, Jeff Layton wrote:
> From: Jeff Layton <jlayton@xxxxxxxxxx>
> 
> Currently, we're capping the values too low in the F_GETLK64 case. The
> fields in that structure are 64-bit values, so we shouldn't need to do
> any sort of fixup there.
> 
> Make sure we check that assumption at build time in the future however
> by ensuring that the sizes we're copying will fit.
> 
> With this, we no longer need COMPAT_OFF_T_MAX either, so remove it.

Sounds like the COMPAT_LOFF_T_MAX should be a separate patch, but otherwise
this looks good.

Reviewed-by: Christoph Hellwig <hch@xxxxxx>

Btw, I seems like arm has another copy of the old broken compat
code in arch/arm/kernel/sys_oabi-compat.c.  I wonder if anyone with
a vested interest in arm would be willing to clean that mess up.