Re: CVS commit: src/sys/arch/aarch64

[Maxime Villard <max%m00nbsd.net@localhost>]

Le 04/08/2018 à 17:24, Ryo Shimizu a écrit :
> > Maybe we should just pass the protection bits in l2_setblocks, and map the
> > kernel text/rodata as RO right away. It would also make it possible to map
> > rodata/data as non executable, with PXN|UXN. (Looking at the code it seems
> > to me rodata/data are executable currently.)
> >
> > We would make three calls, to map
> >
> > 	.text as RX
> > 	.rodata as R
> > 	.data as RW
> >
> > a bit like in amd64[1]. Regarding the DDB ifndef, probably there must be
> > a bit in ARM64 saying "disable page protection", so it could be set when
> > we enter DDB, and we could remove the ifndef.
>
> I get it. I need to write db_write_text(), and when I finish,
> set kernel text/rodata READONLY by default.
>
> Ah...I had forgotten deleting execute bit. We need more 2Mbyte alignment
> between .text/.rodata. I will fix.

I see you fixed it, thanks.

Also, why don't we tag each userland page with LX_BLKPAG_PXN?

It would be nice to set SCTLR_EL1.WXN, by the way.