Re: Avoiding RWX segments in XEN3_DOM0/XEN3_DOMU kernels

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sat, Oct 21, 2023 at 05:12:17PM +0200, Martin Husemann wrote:
> On Sun, Jul 16, 2023 at 10:24:35AM +0000, Taylor R Campbell wrote:
> > The attached patch tries to fix it by splitting the linker script into
> > three different segments -- one with read/execute (for .text), one
> > read-only (for .rodata and various others), and one with read/write
> > (for .data and everything else), along with the note.
> > 
> > Can someone try this and report back, or take a look and tell me if
> > I'm barking up the wrong tree to fix the problem?  (Not a linker
> > script expert here.)
> 
> Works for me - dom0 and domU kernel boot, linker warnings are gone.

Doens't this ends up with bigger kernel images, with a hole between text,
rodata and data ? The hole would be a waste of ram.

Note that this won't change much things in practice: Xen loads this as a
single large blob mapped read/write, and the NetBSD bootstrap remaps
it RX, RO or RW based on __rodata_start and __data_start

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
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