Re: [Linux-ima-devel] [PATCH 1/7] ima: on soft reboot, restore the measurement list

From: Petko Manolov
Date: Wed Aug 10 2016 - 16:14:29 EST


On 16-08-10 14:40:13, David Laight wrote:
> From: Linuxppc-dev [mailto:linuxppc-dev-bounces+david.laight=aculab.com@xxxxxxxxxxxxxxxx] On Behalf Of
> > > > So given what you have above, you'd use something like:
> > > >
> > > > struct ima_kexec_hdr {
> > > > u16 version;
> > > > u16 _reserved0;
> > > > u32 _reserved1;
> > > > u64 buffer_size;
> > > > u64 count;
> > > > };
> > > >
> > > > cheers
> > >
> > > Thanks, I'll make this change.
> >
> > I would suggest:
> >
> > struct ima_kexec_hdr {
> > u64 buffer_size;
> > u64 count;
> > u16 version;
> > };
> >
> > and let the compiler add the proper padding, depending on the architecture. On
> > 32bit machine we'll have 4 bytes smaller allocations (compared to 64bit) while
> > retaining the same functionality.
>
> AAAArrrrgggg.....
>
> That doesn't work for 32bit applications on 64bit hosts.

Which part won't work?

> The extra bytes will make 0 difference to the allocation cost and lots to the
> processing.

An example?


Petko