Re: [PATCH v6 00/12] implement KASLR for powerpc/fsl_booke/32

From: Scott Wood
Date: Sat Sep 14 2019 - 10:35:49 EST


On Tue, 2019-09-10 at 13:34 +0800, Jason Yan wrote:
> Hi Scott,
>
> On 2019/8/28 12:05, Scott Wood wrote:
> > On Fri, 2019-08-09 at 18:07 +0800, Jason Yan wrote:
> > > This series implements KASLR for powerpc/fsl_booke/32, as a security
> > > feature that deters exploit attempts relying on knowledge of the
> > > location
> > > of kernel internals.
> > >
> > > Since CONFIG_RELOCATABLE has already supported, what we need to do is
> > > map or copy kernel to a proper place and relocate.
> >
> > Have you tested this with a kernel that was loaded at a non-zero
> > address? I
> > tried loading a kernel at 0x04000000 (by changing the address in the
> > uImage,
> > and setting bootm_low to 04000000 in U-Boot), and it works without
> > CONFIG_RANDOMIZE and fails with.
> >
>
> How did you change the load address of the uImage, by changing the
> kernel config CONFIG_PHYSICAL_START or the "-a/-e" parameter of mkimage?
> I tried both, but it did not work with or without CONFIG_RANDOMIZE.

With mkimage. Did you set bootm_low in U-Boot as described above? Was
CONFIG_RELOCATABLE set in the non-CONFIG_RANDOMIZE kernel?

-Scott