Re: [PATCH] reduce export symbol CRC table size on 64-bit archs

From: Jon Masters
Date: Tue Jul 14 2009 - 06:30:59 EST


On Mon, 2009-07-13 at 09:44 +0100, Jan Beulich wrote:
> >>> Michal Marek <mmarek@xxxxxxx> 13.07.09 10:11 >>>
> >Jan Beulich napsal(a):
> >> Actually I meanwhile think that module-init-tools can easily detect the changed
> >> layout without any further kernel side adjustments: Since it is known that a
> >> CRC always is a 32-bit value, simply checking whether the so-far-used 64-bit
> >> value has more than 32 significant bits should suffice: If so, the new layout
> >> is being used (with the symbol name starting at offset 4), else the old one is
> >> in effect (name at offset 8). This ought to be a pretty trivial change to that
> >> code.
> >
> >But old module-init-tools will continue reading garbage in this case.

Most of the distros can fix that with a dependency on the kernel package
in the absolute worst case, not that I love that idea, but it happens. I
assume for now we are going with detecting the two possibilities because
it doesn't really hurt in any case to have this support.

Jon.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/